Not only are the Grey's Anatomy writers exceptionally talented in the intriguing style that they write the series' main characters, but they are also skilled at making the patients and passing guest stars very memorable.
An important aspect of the series are the patients. Save a handful that receive multiple episode arcs, most patients come and go within one episode. Having such a short period of time to make these minor characters real and interesting enough so that the audience grows to care about their stories, is no easy task. But most of the time, Grey's Anatomy absolutely nails it.
The series also owes a notable amount of this success to the casting department, as a strong character requires a strong actor. Grey's has always had an amazing cast, and the guest actors are no exception. Let's explore 10 of the series' best guest stars.
10 MANDY MOORE
Mandy Moore was a fitting choice to play the lovable Mary Portman. With her husband, Bill, Mary came to the hospital in season six, for a colostomy bag reversal surgery. She was Dr. Bailey's patient, and someone whom Bailey valued greatly.
Mary and Bailey ended up surviving together during the hospital shooting. Bailey managed to get Mary out of that ordeal alive, but this made it all the more heartbreaking when Mary came back to the hospital to have her surgery, and ultimately died. Bailey performed the procedure perfectly, but after the surgery, Mary simply did not wake up. This obviously was devastating to Bailey. Mandy Moore's sweet character was a tragic loss, but a beautiful portrayal.
9 JEFFREY DEAN MORGAN
Who could ever forget Denny Duquette? Jeffrey Dean Morgan's portrayal of the charming patient made this storyline one of the most well-known on Grey's Anatomy.
Denny was Dr. Burke's patient and was ailing with congestive heart failure. Famously, Izzie Stevens, who happened to be an intern on the case, fell hard and fast for Denny. The two had a heartwarming but very short-lived romance before Denny died of a blood clot after a successful heart transplant.
Denny became probably the most famous guest star on Grey's, and actually appeared in a few seasons, even after his death. As a patient, a vision in Meredith's purgatory, and as a ghost appearing to Izzie Stevens as a symptom of her brain tumour, Denny Duquette is utterly unforgettable.
8 DORIS ROBERTS
Best known for her role on Everybody Loves Raymond as the domineering but lovable Marie Barone, the late Doris Roberts showed up as a patient on Grey's Anatomy in season 7. Roberts' character was a wealthy but bitter woman named Gladys Pulcher, who had been diagnosed with lung cancer.
Gladys' cancer ultimately became terminal, and as she was dying in the hospital, she had no friends or family come to visit her. This prompted Alex to get close to her, and in the end, he wound up convincing her to donate her fortune to his African orphan project. Doris Roberts' appearance on Grey's was short but very memorable.
7 SETH GREEN
Actor, director, and co-creator of Adult Swim's Robot Chicken, Seth Green's appearance on Grey's Anatomy was one of the most memorable.
His character was sweet and charming, Nick Hanscom, who came to Seattle Grace for a tumour resection from Mark Sloan. The procedure was successful, however Mark was only able to cover Nick's carotid artery with a thin flap of skin.
Lexie frequently checked in on and examined Nick, and the two became close. One day, after an attempt to cheer Lexie up, Nick began laughing and his carotid artery suddenly burst, hence setting off the unforgettable scene in which blood sprays all over the room while Lexie desperately attempts to save Nick.
6 TESSA THOMPSON
In season 2, well-known actress, Tessa Thompson, portrayed Camille Travis, Dr. Webber's seventeen-year-old niece. It's revealed that Camille previously had a battle with ovarian cancer when she was fourteen, and this resulted in doctors removing one of her ovaries. But her other ovary was left in hopes of preserving fertility, and upon examining Camille, Addison discovers that the cancer has returned.
Addison informs Adele that Camille's prognosis is not good, and later, this storyline results in the hospital hosting a prom for Camille. Tessa Thompson's portrayal of Camille was one that fans will not soon forget.
5 KEKE PALMER
In season 10, Cristina conducted a clinical trial for people with Hypoplastic Left Heart Syndrome (HLHS). Keke Palmer - famous for her roles in Akeelah the Bee, Joyful Noise, and True Jackson, VP - portrays Sheryll Jeffries, a pregnant seventeen-year-old girl.
Sheryll was hopeful to get into Cristina's trial, as she suffered from HLHS. However, Cristina turned her down, and Sheryll gave birth shortly after in the same episode.While she had very few scenes, Keke Palmer makes the character very memorable with her emotional, compelling performance.
4 JOHN CHO
John Cho has starred in several Star Trek movies, Harold and Kumar, and a couple American Pie movies. But one of his often overlooked roles was his one-episode appearance in Grey's Anatomy. In the series' second season, John Cho portrayed Marshall Stone, a surgical intern from Mercy West.
Marshall's story was a devastating one; due to the exhaustion that comes from being a surgical intern, he fell asleep while driving and caused a severe car accident. In the end, the accident tragically kills a pregnant woman. The scene where Marshall makes a tearful apology to the woman's family is one that remains hard to forget.
3 JURNEE SMOLLETT-BELL
Jurnee Smollett began her acting career when she was a child, appearing on sitcoms such as On Our Own and Cosby. In Grey's Anatomy's fourth season, she portrayed Beth Monroe, a young girl who had a malignant glioma.
The tumour had caused paralysis on her right side, and as chemo and radiation therapy was proving to be unhelpful, Beth was selected to participate in Meredith and Derek's clinical trial. She had been dating Jeremy West, a boy she met at Mayo Clinic when they were both receiving treatments for their tumours. Jeremy also participated in Derek's clinical trial, but the trial's only success was with Beth.
2 ABIGAIL BRESLIN
This famous child actress who had previously starred in films such as Little Miss Sunshine and Raising Helen, had an interesting one-episode role in Grey's Anatomy's third season.
Breslin's character, Megan Clover, seemed to feel no physical pain. Soon it was revealed that she in fact felt no physical sensations of any kind, and Alex, Addison, and Bailey discovered that Megan has Congenital Insensitivity to Pain with Anhidrosis (CIPA). Even though this episode aired way back in 2006, Abigail Breslin's appearance is still an unforgettable one.
1 SARAH PAULSON
The forever iconic Ellis Grey was primarily portrayed by Kate Burton. But in the season six episode, "The Time Warp", American Horror Story star, Sarah Paulson, took on the captivating role.
The episode presents a series of many different characters' flashbacks, featuring instances such as hurtles Bailey had to face when she was an intern, a case Alex and Callie had to work, and most notably, Richard's story about the time he and Ellis attempted to save a man who was ailing with AIDS.
Though Kate Burton is unarguably the ultimate Ellis Grey, Sarah Paulson's performance is an iconic one, and casting her was a perfect choice.