This one can go all over the place. Some men (I tend to think of them as the insecure ones) get turned on by the thought of a virgin because they want to be the first one there.

Other men prefer a woman with experience because there isn't so much awkwardness to deal with and there isn't as a strong an emphasis on emotions.

There are men who are waiting till marriage, so I imagine for them it might be a kind of turn-on.

And then there are men who don't really think one way or the other about it. For them it could be that they are more interested in the relationship and letting the evolve naturally and go where it will than having a specific objective in mind, like sex.

Its really all a personal choice. For men, the question of virginity is largely an external one. Aside from those guys who choose to abstain for religious or personal reasons, most men don't really think about virginity as it pertains to us beyond "When am I gonna lose mine?" After that, each guy develops his own preferences.

Be sure about what you are doing and who you plan on doing it with. If a guy is planning on leaving because you aren't putting out then he isn't worth the time. If you aren't planning on waiting till marriage then do your best to lose your virginity with someone you feel is worth it but don't make the mistake of believing he will be the one and only. I'm not saying it couldn't happen, but that usually isn't the way life works out.

Most important, be safe. Use protection until you are both 100% sure and tested, and even then be mindful of all the possible consequences - from STDs to pregnancy - before engaging in the act. Its true, a lot of people don't think ahead about what they'll do if something should happen. Sex is serious stuff, and a lot can come of it, good and bad. Doesn't mean it isn't one of the funnest ways to spend a rainy afternoon EVER, but you just gotta be mindful of what you're getting into.

Qverb's answer is really great. I agree that men who get turned on by virgins are generally insecure. It's more of a small triumph for them, if they were the first one to get a girl in bed and "claim" her, so to speak. Religious and spiritual reasons aside, I would think the majority of guys would prefer non-virgins simply because there is less anxiety to deal with. Sex is already a complicated and emotional matter, and it probably becomes ten times more complicated when you're dealing with a bonafide virgin.