My boyfriend's hat is a simple 2x2 rib made with a chunky yarn and size 10 needles. I must say, he looks very good (and a bit emo/hippster) in it. I'm still trying to convince him to let me post a picture of him donning the hat.
My hat was made with the following materials (and a size 7 circular needle). I actually wasn't too fond of it when I first finished it, but now I absolutely adore it. While knitting, I got slightly distracted and made it a bit too large, but I really like the slouchy effect I ended with. And I am not posting a picture of me in the hat because I am not a very good model.