Well, I confess to being a fan of science fiction books. Specifically, military science fiction. Honor Harrington rocks
your world. =P
At the same time, I can't say I'm overfond of fantasy books; I generally prefer my amazing and impossible
things to be products of technology instead of magic. Although I do like Harry Turtledove's Videssos books (I need
to read more of them, now that I think about it).
Although it's a similar genre, I'm quite fond of of alternate history stories. I really like Eric Flint and
David Drake's Belisarius series, and S.M. Stirling's novel Conquistador.
From alternate history, I like reading about the real stuff. It's fun reading things like science fiction and
looking at how the author plucked so much of his setting from history. (The setting and situation in the Honor
Harrington novels is heavily influenced by the Wars of the French Revolution, for example.)