Personally you find it much more attractive when a guy is modest. If I compliment a guy and he says something like "no I am so ugly" then it looks like he's trying too hard to be modest or may even seem sarcastic. Instead id rather a guy say "oh thanks" or something like that. Also if I guy was cocky and was like "i know right" after getting a compliment it would make him seem really full of himself which isn't attractive.
So like I said just say thanks or something. Also remember to smile and don't be roo shy. This will make you look confident without seeming full of your self.
I don't understand how some guys say they like girls who don't know how pretty they are. So basically you like girls with insecurities who don't feel good about their looks because you think they won't be as mean to you? No offense but that's pathetic.
I prefer people who are confident. It's okay to know that you're attractive, just don't act like it's the most important thing in the world. Cockiness gets on my nerves, and modesty is just a nice way of saying insecurity. Confidence is that happy medium. Like I'm aware that I'm beautiful and I am confident in my looks but I don't act holier than thou because of it. I know I look good but I don't use it to treat people badly. I don't like people who do that. To me when I hear about a guy/girl that wants a hot person who doesn't think they're hot, it just seems like you want to take advantage of their vulnerabilities.