I watched the entire series for the first time a couple days ago (excluding Korra) and I can't stop thinking about the show, wanting more, angry because there's only three seasons. I'd go as far as to say this is one of the 1000 shows you should watch before you die.
Ew: Operation is a must.
.
After operation,
Me: What did you do to me?
Ew: I took away your knees.