I can't really answer this fairly because I don't know many gay guys and all (mostly) my friends are as straight as possible, do I have something for some of them? Yes, but I'd say that's just me liking people I know and wanting to go a bit further on our relationship, I don't think it has anything to do with them being straight.
It's not like I want to DATE a STRAIGHT person, I think that's what's weird and maybe what happens to some of you. I want to date them because they attract me and I know if I ever end up being with someone like this I KNOW they are gay and NOT straight. I don't know if this makes much sense.
There aren't many gay people around here (or that I know of), so obviously it's easier to fall in love with a straight person, but that's it.
I'd say 50/50, anyway.