If the guy can pull it off I love facial hair. I think it looks really sexy. And not just stubble, screw stubble that just looks sloppy. I don't like mustaches, they creep me the hell out. But I love beards or sideburns or any of that stuff. I think it's just so manly and sexy. Not to mention my neck is really sensitive so when my boyfriend kisses it and his beard scrapes against it lightly it feels so good, gives me tingles. However not long beards. Beards that are actually long and bushy are a little weird, unless you can really pull it off. Then it's awesome and badass.
In general, I'd say clean-shaven, but there are loads of exceptions. A bit of facial hair/stubble can be sexy, and there are a couple of guys I know who look fantastic with facial hair, to the point where I can't imagine them without it. In fact, the guy I'm interested in now has a chinstrap which I expected to hate, but it actually looks amazing on him. :P
I'm not a fan of huge, full beards/moustaches, though-- I've always associated them with older guys.
i love facial hair its such a turn on when were making out and its rubbing against my neck; or better yet rubbing against my thighs xD. now I'm talking here about gruff, or maybe a goatee or side burns. but I don't do any guy who has like a lumber jack full on beard that's so ew