For fourteen years, viewers have passionately tuned in on a weekly basis to see the often melodramatic adventures of the characters of Grey's Anatomy.
As the bedrock series of both Shondaland and TGIT, this soapy medical drama has never once flagged in the ratings, consistently posting some of the strongest drama returns for any network drama - even with considerable cast and crew turnover.
From the beginning of the series, the show has traced the journeys of medical residents, interns, doctors, and higher ups at Seattle Grace Mercy West Hospital, now known as Grey Sloan Memorial Hospital.
Whether you were a fan of McDreamy or McSteamy, or felt that the loss of George was your breaking point, or maybe Lexie, or Mark, or whether you wanted to be a Twisted Sister with Cristina and Meredith, the show has always offered characters who you wanted to root for.
However, they've also arguably offered some of the most obnoxious characters on primetime television. Characters on this show come and go far more frequently than they do on most other series, but the length or brevity of a character's stay on Grey's doesn't make a casting hit or miss any less significant.
With that said, here are the 7 Casting Decisions That Saved Grey’s Anatomy (And 8 That Ruined It).
15 Ruined: Camilla Luddington
Grey's Anatomy has tackled countless important social issues and struggles over the course of its run, including addiction, PTSD, and countless under-represented conditions and diseases.
With the introduction of Jo Wilson, although it took a long time to get there in a particularly roundabout way, Grey's has given itself a very complex abusive relationship storyline.
With the reveal that Jo was in fact a woman named Brooke on the run from her abusive husband Paul, the milquetoast character should habve suddenly become reinvigorated with energy and interest.
However, due to Camilla Luddington's mediocre acting skills, Jo/Brooke's storyline has only become all the more muddled and difficult to endure.
The messages Grey's has been sending about empowerment and strength in the face of abuse, and of survivors standing together, are surely important things to give a platform to. But Jo, and Luddington, were undeniably the wrong choice for that soapbox moment.
14 Saved: T.R. Knight
It was the loss that ruined fans all across the world: George was 007, the unrecognizable victim of the horrific bus crash. His death in the fifth season finale of Grey's represented a real moment of change for the series, as the stakes were raised to an entirely different level with the first significant loss of a main cast member in an entirely permanent way.
George had always been the adorable, affable little brother type character, always good for a laugh and a hug and words of comfort when they were needed.
He was also a damn good doctor, regardless of whether he was able to admit it to himself. Even if he didn't have the best of luck in relationships, he was still impossible to hate, a true friend who would always be there.
Unfortunately for Grey's, T.R. Knight would not always be there.
His sad and complicated behind the scenes exit after five years on the series left one of the most noteworthy gaps the series had to scramble to fill. No character has ever really been able to replace him - but then again, that's exactly how it should be.
13 Ruined: Brooke Smith
Sometimes, characters are introduced who may have had an original intention, but are ultimately relegated to serving the purpose of furthering another character's journey.
In the early years of Grey's, Erica Hahn is perhaps one of the most glaring examples of this plot device conversion -- and one of the least successful, at that.
As a romantic interest for the spitfire Callie Torres, Hahn proved to be entirely the wrong choice. With a complete lack of chemistry, a grating personality, and not much of a script to go off of, Erica Hahn failed to become much of a screen presence worth paying attention to.
Perhaps that is the fault of the writers, for never developing her in any meaningful way. However, perhaps the fault can also be attributed to actress Brooke Smith, whose performance never seemed to click with anyone she shared the screen with, but stood out most of all against Sara Ramirez's Callie.
12 Saved: Eric Dane
Making a sympathetic character out of someone who ostensibly began the series as the other man -- to his best friend, no less -- is certainly no easy feat.
However, somehow, Mark Sloan became one of the most beloved doctors to ever roam the halls of Seattle Grace Mercy West -- so beloved, in fact, that the hospital would be partially renamed in his memory after his untimely death.
On the outside, Mark -- affectionately known as McSteamy -- is all charm and bravado; but on the inside, he reveals a deeper vulnerability and raw emotion, often glimpsed over the course of his tragically fated relationship with Lexie Grey.
Through his friendship with Derek Shepherd, tried and tested as it may have been, viewers also came to know a whole other side of him, one that could be supportive and light-hearted in equal measure.
Thanks to Eric Dane's nuanced performance, Mark Sloan became so much more than the McSteamy audiences initially wrote him off as.
Instead, he became one of Grey's most iconic male characters.
11 Ruined: Jeffrey Dean Morgan
Romantic relationships on Grey's have essentially become a dime a dozen at this point -- and honestly, they have been for a while. However, perhaps one of the most ill thought out romances found Izzie Stevens falling deeply (and quickly) in love with heart patient Denny Duquette.
Their story had some sweet moments in the beginning, but any potential value that the storyline may have originally offered was soon sharply undercut by later seasons using Denny in the role of a ghost. Certain particularly tasteless scenes -- including Izzie engaging in a romantic relationship with Denny's ghost -- just made matters even worse.
Jeffrey Dean Morgan may have done as best as he could with the material he was given, but his Denny was charisma-free and borderline creepy.
This made his forced connection with the much younger Izzie come across as awkward from the start.
10 Saved: Chandra Wilson
To put it simply, Chandra Wilson has spent fourteen seasons on Grey's as nothing short of a powerhouse, and the four Emmy nominations she earned for the role of Miranda Bailey more than attest to that fact.
However, no matter the critical acclaim she received, her portrayal of the constantly rational and wonderfully inspiring Bailey is consistently overlooked -- and it's about time that change.
Perhaps more than any other character on the series, Bailey is committed to doing what is right, no matter what the cost. She fights like hell for every patient she has, and she fought hard as she could to save a marriage that was unfortunately destined to fail.
As tough and passionate as she may be, Wilson has also worked to allow viewers see the softer sides of Bailey all along, including in significant moments such as naming her baby after the late George -- who was, as she herself admitted, her favorite of the residents.
9 Ruined: Caterina Scorsone
Grey's has been a show with a whole lot of dysfunctional families since it first aired, whether it be the Greys or the Averys or the Burkes. Parent-child relationships have been particularly fraught, if not outright abusive.
There has also been some sibling to sibling tension over the years, with Meredith struggling to accept her suddenly extended family on more than one occasion.
However, no sibling came with a more frigid welcome than Derek's self-destructive sister, Amelia.
Crossing over from the tepid spinoff series, Private Practice, Amelia brought with her endless amounts of baggage and similarly endless scenery chewing from her portrayer.
Caterina Scorsone is often tasked with truly traumatic subject matter, ranging from addiction to the loss of a newborn child, but her acting has never been strong enough to carry the load. Paired opposite much stronger actors, such as Patrick Dempsey and Kevin McKidd, there was never a way in which she could properly compete.
8 Saved: Patrick Dempsey
Grey's may be known for shocking twists and tragic losses, but the sudden death of Derek Shepherd was a twist that truly no one saw coming -- and honestly, one that the show hasn't yet rebounded from creatively.
A perfectly flawed foil to Meredith Grey's lead, Derek Shepherd was charming and vulnerable, intelligent, and unsure.
He was also full of so much goodness and empathy that he truly personified what it means to not only be a good doctor, but a good man. He made plenty of bad choices, but he showed remorse each and every time - and grew all the better and stronger for it.
Flawed male leads are fairly common on television nowadays in the age of the antihero, but what sets these characters apart from one another is often the strength of the actor's portrayal.
It's hard to imagine any other actor imbuing Derek's character with such warmth and pain in the way that Patrick Dempsey did. It's also so beyond safe to say that the show is lesser without him.
7 Ruined: Sarah Drew
Playing the straitlaced, serious, reserved character is never an easy feat -- especially nowadays in the age of snap judgments while livetweeting. April Kepner has been a thorny character from her introduction, persnickety and sanctimonious and judgmental of nearly everyone she came into contact with.
Over time, she loosened up, engaging in a very messy relationship with Jackson Avery that left them both changed for the worse. As she grew less reserved, her judgmental nature only grew, and her melodramatic behavior along with it.
April has endured a lot of loss, ranging from the failure of engagements and marriages, to the loss of her newborn child.
Yet no matter how dramatic the scenarios may be, and how tragic the scenes and feelings she is meant to express, Drew's acting has never elevated beyond the level of melodrama, ranging from overwrought to underperformed with startling frequency.
6 Saved: James Pickens, Jr.
Dr. Richard Webber is an often unfortunately overlooked character. As he was a mentor to the group of young residents we followed through their journeys, he was easy to brush off and not consider to be worth as much attention as the rest of the ever-changing gang.
However, over the course of Grey's fourteen seasons, Dr. Webber has consistently served as the series' emotional center, always ready with advice and counsel.
Even as he dealt with his own struggles -- his alcoholism and its impact on his career, his wife, Adele's, Alzheimer's, and his regrets and memories of his affair with Ellis Grey -- he is always willing to extend a helping hand and a kind word.
Through the vastly underrated performance of James Pickens, Jr., Richard brings a necessary feeling of reason and rationality.
He also brings gravitas to a series that is often so very far removed from those same things.
5 Ruined: Jessica Capshaw
You'd be hard pressed to find a show on television filled with a larger number of beautiful, selfish people doing ugly, selfish things than Grey's Anatomy. Over the years, almost every single character has done something so ugly and so out of their own self-interest that you can't help but lose the desire to root for them.
Yet even among all that selfishness, one character -- and shaky portrayal -- stands out: Arizona Robbins, as portrayed by Jessica Capshaw.
Whether cheating on her long-suffering wife Callie, or engaging in an ugly prolonged custody battle, Arizona's influence is clearly a toxic one.
Her character may have been important for the increase of representation of LGBTQ characters on television, but Arizona is hardly an icon worth praising. Her ugly flaws, in addition to Capshaw's grating performances, make her character near insufferable.
4 Saved: Sandra Oh
"Screw beautiful. I'm brilliant. If you want to appease me, compliment my brain." How could you possibly summarize Cristina Yang any better than that?
Uncompromising, bold, brave, and brilliant, Cristina's arc from the very start of Grey's was driven by the pursuit of greatness. Determined to become the best surgeon she could be, she never let anything stand in the way of achieving her dreams, even if it meant letting go of other aspects of her life, such as key romantic relationships.
Even as she pursued her career dreams above all else, Cristina allowed herself moments of vulnerability, both of the heartbreaking kind -- her breakdown after Burke left her at the altar -- and heartwarming kind -- as can be seen in her deep friendship with Meredith.
Thanks to the strength and conviction of Sandra Oh's stellar performance, Cristina cemented herself from the start as one of the show's strongest and best characters to date.
3 Ruined: Kelly McCreary
We know, we know -- it's a soap opera. Surprise siblings are more or less part of the DNA of these kinds of shows. Shocking paternity reveals are the bread and butter that melodramatic goodness thrives on. However, the reveal that Meredith had yet another surprise sister was already pushing the limit of what we were willing to accept.
Maggie Pierce would have been an annoying, albeit tolerable character if the casting for the role had been done well.
However, Kelly McCreary's performance often leaves the viewer with the feeling that Maggie is simply just someone who tries so very hard to fit in somewhere where she was never meant to be in the first place.
What makes her character the hardest to tolerate, however, is the recent development of romantic tension between Maggie and her step-brother, Jackson Avery. As if the romantic relationships on this show weren't usually toxic and messy enough, do we really have to start getting all Game of Thrones around here?
2 Saved: Chyler Leigh
Grey's Anatomy may intend to refer to Meredith with its title, but there's only ever been one Grey who was always worth rooting for: little Grey herself, Lexie.
If Meredith has always been known to be the logical one who makes bad decisions, Lexie was the one who acted with her heart and almost always chose right in the end.
Buoyed by Chyler Leigh's incredible performance, Lexie offered a center of light and warmth for the entire cast of characters across her entire tenure on the series.
Unafraid of being vulnerable and open with those who mattered most to her, Lexie was perhaps the most profoundly human character on the show, accepting everyone scars and all and struggling with her own demons along the way.
Her tragic death was arguably one of the show's biggest mistakes, not only for the loss of love and light she offered all around her, but also for the failure to keep the effortlessly talented Leigh as part of the cast.
1 Ruined: Katherine Heigl
From the very beginning, ranging back to the days of the group of residents known as M.A.G.I.C., Izzie was by far the weakest link of the main cast. Bratty, entitled, and sharply judgmental, her character had few likable moments long before it came to light just how difficult her portrayer could be.
The behind the scenes drama between Katherine Heigl and Shonda Rhimes is the stuff of Hollywood legend at this point, as is the way in which Heigl's career has spiraled downward since Izzie exited Seattle Grace all those years ago. Heigl's acting was never strong enough to match up with some of her scene partners' skills.
Add to it the flimsy characterization that Izzie was given beyond her self-interest, and her refusal to acknowledge her fault in any of the messes she created, and it's pretty safe to say that Heigl -- and Izzie -- were perhaps Grey's biggest mistake to date.
What do you think were the best and worst casting choices for Grey's Anatomy? Let us know in the comments!