T.R. Knight as George O’Malley
One of the biggest tearjerkers on this list, at the end of season five, George had just decided to enlist as a trauma surgeon in the army and was on his way to do so when he saved a woman from getting hit by a bus, only to be hit himself. He was in such bad shape when he got to the hospital that no one recognized him until he used his finger to write his nickname, 007, in Meredith’s hand. They were unable to save him, and he tragically died.
After several tumultuous seasons behind the scenes (including Isaiah Washington using the f-word while allegedly referring to him), Knight struggled with some of George’s storylines and the fact that George barely appeared in the beginning of season five, and asked to be released from his contract.
Knight returned to Shondaland in 2017 for an arc on The Catch, and has also appeared on The Good Wife, 11.22.63, and Genius, among other series. In 2019, he appeared on The Bravest Knight and in 2020, he appeared in HBO Max series The Flight Attendant with Kaley Cuoco. He also returned to Grey’s for one episode to meet Meredith during her COVID-19 coma.