Undateable: 311 things that guys do that guarantee that they won't be dating or having sex by Ellen Rakieten and Anne Coyle, it's a funny and truthful book about what makes a man go from be boyfriend potencial to be a laughing matter between you and your girlfriends, like wearing tight whities or having an action figure collection (and be 25 years old). And all the things are right. Sad but true. For more details check out the site and the presentation video.
What would make you never date a guy?