"A Soldier Erect" by Brian W. Aldiss

I just finished this. It was recommended by my Nam-veteran father, who said it was pretty much spot on about what it's like to be a young soldier in a tropical hellhole. It's really, really good and extremely funny.

"Lolita" by Vladimir Nabokov

This is definitely my #1 HOLY SHIT book. Not only is the writing so good as to be transcendant, but it's funny as hell and it's an American classic or whatever. Seriously you should read this, though.