Yes, looks are important. In dating, personality is a HUGE point, but if you aren't physically attracted to someone in any way, then I don't think a relationship would ultimately work out. In hooking up, I would assume looks are the most important because all you're doing is being physical.
In a guy I look for someone that can put up with me and will be willing to tell me when I'm wrong. I know I need that. I don't like guys that agree to everything I say. I like to fight my opinion, especially when I feel strongly about something. I look for a guy that has a passion and a drive. Also, the guy must like kids- not because I plan on having kids anytime soon, but, I think it says a lot about a guy if he doesn't like kids.
Looks matter and only ignorant people will make the claim they dont. I'd never sleep with someone I found physically repulsive and nasty. Who in their right mind would? I don't give a **** how *great* their personality is