According to friends, really nice + really caring. Even some friends say that I'm the 'nicest guy they know'. I don't see how, as I'm nice to pretty much anyone. I mean, if you're respectful/nice to me, then I'll wholeheartedly return the favour. Maybe, those friends' friends don't do that for them? Haha.
For me, I'll say my defining characteristic is quietness/shyness. It's awful, but I'm certainly working on it. Hopefully, working on Let's Play's and eventually streaming will help get rid of it.