I'd put myself between 90-99% straight on here.
For the following reasons:
1. All my sex partners from handjobs to intercourse have been women.
2. All the people I've desired and fantasized about have been women.
3. I'm not sexually aroused by men in the slightest.
4. Never had any sort of sexual contact with a man, and wouldn't for any reason, barring rape, or perhaps a billion dollars and a guarantee of world peace and prosperity for all.
5. I don't have a problem with seeing other men naked on here. I'm here to compare.
6. I don't mind the flirting or admiration I get from gay men on here, but I know it isn't anything other than my human desire for appreciation and flattery, and a not a desire for anything more.
7. I enjoy anal stimulation. What can I say, it gets me hard to have something stimulating my prostate. So I do enjoy sticking things in my ass. I also like and get off on porn involving female-on-male strap-on sex and on the idea of doing this with a woman.
I'd say that #7 is primarily the reason I put a little "Gay" in for my percentages,mostly a minor nod to the fact that most straight guys aren't into things going into their ass, but I've explained elsewhere that I think it would make me a little more "queer" than "gay", at least as I understand the terms.
These percentages will never be anything more than a guideline to people's sexual orientation, not a hard, exact, and clear rule.