Well i like romantic fantasy, but I know some of those are actually really popular with guys. Sara Douglass' wayfarer redemption is popular. If you don't mind reading something, um, sexually graphic, you can try Kushiel's Dart by Jacqueline Carey (I was amazed with the amount of guys who loooved those books. i did too, but i'm a girl..)

Ooh Green Rider by Kristen Britain is great too, not as much a chick thing. First two are out, and the third still doesn't even have a title yet :wtc: try that one if you aren't sure about fantasy (its really starting to gear towards women).