I don't think gay men are more likely to do drugs because they're gay, I think it's because of the consequences of being gay. Just that general mistreatment combined with a dash of malaise and a pinch of what-the-hell-do-I-realistically-want-out-of-life. It makes for a dissatisfied existence, which the rollercoaster of modernity, aka drugs, remedies temporarily.
Soooo.... that said, it's just that gay men are more likely to do drugs because they're dissatisfied with life. It's not because we like penis.
My experience with drugs runs the gamut... never tried crack, heroin, ecstacy, or LSD. The last two I will probably try at some point in my life because I'm curious and those both sound crazy fun. The first one I don't even have the urge to experiment with. For whatever reason, it's just totally unalluring. I couldn't do heroin intravenously because of my crazy hardcore needle phobia; I hate when they draw blood and that's taking something OUT of a vein, I freak when they try to put something in one.
Everything else, you name it, I've tried it. There's only been a couple I've REALLY liked. It's more like they were all good jokes or stories, y'know? Every once in a while, you remember them, pull them back out for use, and then store them away for later. I think I'd get pretty bored with a drug if I did it every day, same as if I watched the same movie every day.
Personally I don't see why there's such a huge stigma on drug use. It's just another thing to do. I also think part of the reason drug use is such a problem is the stigma. People can't make educated, sound decisions because drugs are illegal. People know nothing about dosage, effects, complications, counterindications, etc. Drugs are like going to the movies, IMHO. You risk crashing on the way to the movies, but you know you wanna see the movie. If you drive safe, there's not much risk, so you go for it. It's fun, and it's somewhat safe fun, so long as you're careful.
But now I'm letting my drug advocate side get way too apparent... so I'll hush now.