Why do I fancy hardly any women? is it normal?

Other guys say, oh she looks nice, look at the t*ts on her and so on and so fourth with certain girls we see, and they do nothing for me. I say, yeah she's alright. I'm definitely not gay either before that enters your head. Think I'm destined to be single. I only seem to fancy really attractive slender women and I think they're out of my league 90% of'em, or better looking guys get in there first. I'm not ugly though, I'm not Brad Pitt though either, but I'm not that bad, about the same as say Gary Barlow or somebody like that!