Both. Relationships need physical attraction just as much as they need personalities to be compatible. What matters most is personality though, because weirdly enough, that could make an average guy more attractive or a hot guy repulsive.
For me, I like guys who can make me laugh and smile, and who always make me feel good, like I'm one in a million. Also, I love smart guys. Athletic is always nice, too. Confidence is good, but when it turns to cockiness, it's a major turnoff. I like when a guy is sweet to me and makes an effort to talk to me, and maybe hang out. The confidence to ask a girl to hang out is awesome.
both. There has to be physical attraction and we need to like a guys personality. If a guy is super confident and has a great personality and is only average looking, girls will still fall for him because his personality will make him more attractive.