You say thank you and move on.
You just say "thank you," and that's that. If you're interested in him, perhaps use that as an opportunity to strike up a conversation. Undoubtedly, that's one of the reasons he said it in the first place.
A simple smile and a thank you is fine.
If you think he's cute then ask him if he'd like a blowjob!!
yeah right, why would i want to go through that whole thing again? they're so disgusting, i mean you have all this sticky crap on your face even if he didnt cum yet, its really not fun at all to give and i suggest you dont if you know whats good for you..
Are you kidding? Blowjobs are gross? Honey, find the right person and you'll think differently. I used to think the same thing and I hated giving them, but then I found my true love (my fiance) and now I love giving them to him. When you're in love, it's a whole different experience - trust me! When you're in love, everything and anything sexual can be great. By the way, just because you give a blowjob doesn't mean you have to let him cum in your mouth or on your face (to avoid more of the "sticky crap" as you so put it). I give them and love it, but I still don't let him cum in my mouth (I just don't like the taste) and he's fine with that. I usually suck for a while to get him going and give him some good pleasure, then he takes it out of my mouth and finishes himself off by making love to me. He would much rather cum inside me than in my mouth anyway.
Anyway, like everyone else said--say thank you when someone tells you that you're pretty but if they seem like they're being a pig and just saying it because they want to get down your pants or something, then tell them to fuck off.