As an atheist I don't believe in either but if I had to choose one I think I would pick hell mainly because if all the sanctimonious, judgmental pricks who spend their days telling everybody they are going to heaven actually get there then I really don't want to spend an eternity with them.
Conversely if you look at all the people they have consigned to hell and all things that we do that can get us sent to hell I really do think it would be a more interesting place to go.
Heaven really has a lousy marketing plan.