First, there are two books that stand out because some of the most gorgeous men in the world grace the covers (not to mention that the material inside is pretty good too).
The cover of Annie Proulx's Brokeback Mountain speaks to me. Of course it is just like the movie cover, but cut me some slack on this one! I just like to stare at it.The other is Scott Heim's Mysterious Skin...same scenario :) I mean, just look at him.
I also find the cover to Alice Sebold's The Lovely Bones to be pretty intriguing and then after you read it, it is very telling- like foreshadowing.
Another book that I just finished recently, Chris Lynch's Inexcusable, is another cover that intrigues the reader and makes you want to find out what this field and half-covered female have to do with one another.
A final book cover that I think is really neat is Mark Haddon's The Curious Incident of the Dog in the Night-time. The cover plays along with the theme of a colorful and unique narrarator.