Just finished Laura Levine's Killer Cruise, a mystery novel which made me chuckle on every page, and then laugh out loud at the end. Levine is a comedy writer who wrote for TV shows including Three's Company and Laverne and Shirley.
The Hitchhikers Guide set by Douglas Adams. (You know, a trilogy in five parts.)
If you haven't read this series, you are missing out on some serious hilarity. And if you have only seen the movie, you are missing out even more. A lot of the word play of the written book simply cannot be carried over accurately to film.
Eat Pray Love by Elizabeth Gilbert made me laugh on nearly every page. She has a natural flow to her sense of humor and sneaks it in on you, which is great.
Ditto for the Hitchhikers Guide to the Galaxy, just like a Monty Python sketch, it just gets better and better with familiarity, the more you know which joke is coming next the funnier it gets!
I thought Christopher Moore's "The Stupidest Angel" truly funny, especially with *SPOILER ALERT* dead people bantering back and forth in their graves like they alive and walking around!