My boyfriend doesn't notice it very much in himself, but he absolutely 100% bases his opinion about people on looks. When we're watching films, if the pretty girl does anything stupid then she can get away with it in his eyes.
We were outside the other day and there was an ugly homeless woman singing for money, and I commented on how her voice was absolutely beautiful. He took one look at her and said that her singing was awful, so I told him that I could bet him whatever he wanted that if it was a beautiful woman, he would say she was a good singer. He thought a little bit and then he actually admitted that I was right.
Edit: I still absolutely believe that men have it harder than women when it comes to relationships. I think it's pathetic that people blame the other sex for not liking them though. No one owes you anything, and the phrase "everyone deserves to be loved" couldn't be any less true. By saying that you deserve love, you're essentially saying that other people have an obligation to love you... that's a disgusting concept in my opinion.
Skewing your whole perception of someone simply because of their appearance is pretty horrible though.