Katherine Heigl – Izzie Stevens Then
Izzie was a tenacious character who overcame a tough upbringing to become a successful doctor. She fought hard to save her patient and love interest, Denny, but was devastated when he passed away.
After being diagnosed with cancer, Izzie married Alex Karev but was later fired and left the show in season six. Katherine Heigl's departure from Grey's Anatomy was marred by tension, reportedly due to her withdrawing her name from an Emmy nomination.
