Introduced near the end of Season Two as the love interest of George - and now his wife - this orthopedic surgeon is not afraid to ruffle the interns' feathers.
Dr. Calliope "Callie" Torres first appeared in episode the "What Have I Done to Deserve This?" She met George when treating him for a dislocated shoulder, which he suffered falling down the stairs... fleeing Meredith.
While she appears to be a strong woman on the surface, Calliope clearly has her insecurities. She grew defensive after being criticized by Izzie for not washing her hands after using the bathroom, and actually lives in the hospital basement, as discerned by George in "The Name of The Game."
Yet she clearly adores Dr. O'Malley, which dawned on Izzie eventually, as the blonde beauty famously noted, "Oh my god... George is her McDreamy!"
In the episode "17 Seconds," Callie proclaims her love for George, later revealing that this was the first time she said that to a man. While he didn't say it back, he admitted that he wanted to give himself the chance to. Callie replied that she "hates that she's so into" George.
But she is, just the same. Despite breaking up with O'Malley early in Season Three and having a brief fling with Mark Sloan, she realized she wants to be with George and married him in Las Vegas - possibly in haste after his father had just died. She is not aware he soon had a drunken affair with Izzie, although Callie sure has her suspicions and is determined to keep her man.
Lexie: [narrating] Grief may be a thing we all have in common, but it looks different on everyone.
Mark: It isn't just death we have to grieve. It's life. It's loss. It's change.
Alex: And when we wonder why it has to suck so much sometimes, has to hurt so bad. The thing we gotta try to remember is that it can turn on a dime.
Izzie: That's how you stay alive. When it hurts so much you can't breathe, that's how you survive.
Derek: By remembering that one day, somehow, impossibly, you won't feel this way. It won't hurt this much.
Bailey: Grief comes in its own time for everyone, in its own way.
Owen: So the best we can do, the best anyone can do, is try for honesty.
Meredith: The really crappy thing, the very worst part of grief is that you can't control it.
Arizona: The best we can do is try to let ourselves feel it when it comes.
Callie: And let it go when we can.
Meredith: The very worst part is that the minute you think you're past it, it starts all over again.
Cristina: And always, every time, it takes your breath away.
Meredith: There are five stages of grief. They look different on all of us, but there are always five.
Callie: Did anyone ever think you two were a couple?
Meredith: No, because we screw boys like whores on tequila.
Cristina: Then we either try to marry them or drown ourselves.