The main cast of Grey's Anatomy is absolutely massive, and has really built itself up over the years. The first couple of seasons were focused primarily on the original interns: Meredith, Cristina, George, Alex and Izzie, but as the show progressed, more characters got their own chance to shine.
However, because Grey's has been on air for so long, it's natural that most of cast eventually move on. When that happens, sometimes their characters get a really amazing send off. Unfortunately, not all of the cast are that lucky, and there have been some pretty questionable exits from the series as well.
BEST: Cristina Yang
For the first ten seasons of Grey's Anatomy, Cristina Yang basically served as the co-lead character alongside Meredith Grey. These two budding surgeons were incredibly close and they were more than just best friends: they were the twisted sisters.
Due to the importance of the character to the series overall, Cristina was given a long and perfectly executed storyline, in which she was nominated for the Harper Avery Award, and left Grey Sloan Memorial to run her own department in Switzerland. Her farewell episode is regarded by fans as one of the show's most emotionally satisfying.
WORST: Shane Ross
Although Stephanie Edwards and Jo Wilson turned out alright, the third group of interns to grace the halls of Grey's Anatomy were not that appealing to viewers. Shane Ross first appeared in Season 9, where he actually appeared to be quite likeable.
Soon, though, his character took a drastic U-turn in the following season after he caused a fellow intern's death. He became moody, rude and withdrawn, and no one really liked him. His exit was equally weird, as he decided at the last minute to go with Cristina to Switzerland.
BEST: Derek Shepherd
Many fans might disagree with this entry, but the fact is that Derek's exit from the show was a lot better than many of the other characters. By the time Season 11 came around, Derek was a pivotal part of the series, as he was married to the lead character.
Derek and Meredith had two children by this point, and so to have Derek walk away from all that would just have been wrong. The only proper way to write out Derek was to kill him, and the producers made his death about as heartbreaking as they could get.
WORST: Callie Torres
Callie Torres was a bit of a funny character, as she was quite annoying in her first couple of seasons. Things turned around when she began to come out, and she gained a lot more confidence and quickly became one of the best characters on Grey's Anatomy.
However, a bit of her character growth was subsequently undone in her final season on the show. In Season 12, Callie dated one of the doctors who killed Derek, and then forced everyone to go through a very painful custody battle just so she could take Sofia to New York.
BEST: Arizona Robbins
Arizona Robbins was one of Grey's Anatomy's perkiest characters, so it made perfect sense that she got her happy ending. For the longest time, Arizona was one half of the power couple known as Calzona. However, the couple got divorced in Season 11.
Despite their divorce, Arizona and Callie both remained friends, and they also shared a daughter together, Sofia. In Season 14, though, Sofia began to miss her other mom and started acting up, so Arizona moved to New York to be closer to Callie (apparently in more ways than one).
WORST: Izzie Stevens
Izzie Stevens was one an original intern on the show, so the fact that her exit was so underwhelming was just really disappointing. Before her departure, Izzie had been part of one of Grey's Anatomy's biggest storylines: her love affair with Denny Duquette.
Izzie then got diagnosed with life threatening cancer in the show's fifth season. She fought with everything she had and eventually beat the odds in Season 6, only to leave the show a few episodes later because she felt as though she didn't belong in Seattle anymore. She would return in one of the show's most outrageous and controversial twists (more on that later).
BEST: Mark Sloan & Lexie Grey
Although these two are separate characters, they have been often paired together because they left the show in the same, tragic way. Mark and Lexie grew to be two of the most loved characters on the series, and their relationship was to die for.
Sadly, they were very much two star-crossed lovers, for they were both victims of the plane crash that occurred in the Season 8 finale. Lexie died on the scene, and Mark slipped into a coma soon after. Before they died, they both declared their love for each other.
WORST: Erica Hahn
To be honest, Erica Hahn was not a very pleasant person. She was extraordinarily arrogant, and highly competitive, especially with Preston Burke. When she joined the show as a series regular, her treatment of Cristina was absolutely deplorable.
Hahn's only real redeeming feature was her relationship with Callie, but even that turned sour when she exclaimed that it wasn't possible for Callie to like both men and women. With that blatant bi-phobic remark, Hahn walked away, never to be seen again.
BEST: Stephanie Edwards
Stephanie was probably the best character out of her batch of interns. Although she could be a little irritating, she more than made up for it with her sass and her undeniable surgical skills. Plus, she was a real friend to Jo.
Stephanie's exit was also probably the most dramatic exit in the whole of Grey's Anatomy, as the entire Season 13 finale was focused on her and her efforts to save a little girl from a massive fire raging through the hospital. It was a truly terrific episode.
WORST: Alex Karev
Alex Karev's exit was extremely controversial, and his departure left the Grey's Anatomy fandom totally divided. Alex had been a beloved mainstay of the series for over fifteen seasons, until he made his last appearance in episode 8 of Season 16.
Fans actually didn't know that this was to be his last episode at the time, and his farewell episode that came later on in the season offered an almost unbelievable solution: Alex abandoned his loving wife to go be with Izzie, who had left him years before and hasn't been heard of in the series for the longest time. Additionally, he and Izzie actually had two children together.