Thats really hard to decide because I've read about so many great fictional guys. I'm going to say Either George Weasley From Harry Potter. Or Seth Clearwater or Jacob from twilight. I wouldnt pick Edward because there is no way I would marry a vampire no matter how hot he is.
Edward Cullen (obv.)
Any HP character... but more specifically, Dean, Seamus, Oliver, Harry, Ron, Fred, George... etc...
Has anyone said Jack Sparrow from PotC yet? Yes, he's a drunken lunatic, but my God, is he a hot drunken lunatic.
The Doctor :)
Jem, once he's older, from To Kill A Mockingbird.
Akkarin, from the black magician trilogy
Ok, pretty much every book I've ever read contains someone I want to marry.