When we first got to know Dr. O'Malley, he harbored a secret crush on Meredith, with whom he shares a house, from day one. George also has a host of other insecurities. His positive outlook on life, and the fact that he is more emotional than most men, often lead to conflict with other doctors.
George doesn't fit in with his own family, either. A Thanksgiving hunting trip resulted in a George unloading a lot of emotional baggage during a conversation with his blue-collar dad and brothers (one of whom later shot the dad, forcing George to operate).
A friend and confidant of Izzie, George won praise among the entire hospital staff for saving a man's life in an elevator during a power failure. With Dr. Burke talking him through it, George stopped the bleeding in a patient's heart single-handedly after Alex choked under pressure.
After great inner strife, he admitted his feelings for Meredith and slept with her in a moment of peak vulnerability for both. After some disastrous fallout, he moved out of her house and onto Dr. Burke's sofa. He remained there until Season Two came to a close - and he found a spot in bed next to his girlfriend, Callie Torres.
In the hospital basement.
Season Three was a tough one on George O'Malley. His father had a heart surgery, then succumbed to cancer. He and Callie broke up, then married in an impromptu Las Vegas ceremony. Then he drunkenly slept with his best friend, Izzie, and has doubted his future with Callie ever since. No one knows where the carousel that is George's personal life will stop, but one thing is for sure - it's a bumpy ride.
MEREDITH: [to Derek] "I am a sink with an open drain, and anything you say runs straight out." [storms off]
GEORGE: "She probably could have used a better metaphor."
IZZIE: "Give her a break, she's got a hangover."
CRISTINA: "There's a club. The Dead Dads Club. And you can't be in it until you're in it. You can try to understand, you can sympathize. But until you feel that loss... My dad died when I was nine. George, I'm really sorry you had to join the club."
GEORGE: "I... I don't know how to exist in a world where my dad doesn't."
CRISTINA: "Yeah, that never really changes."