While I was here posting, I just had to say, NorCaliGreenFiend, that ITA about Vonnegut. I haven't read any Palahniuk (yet); but I certainly plan to now.
Anything done by Dave Barry. Pontoon by Garrison Keillor. Superman by I forget who. All of those I would recommend.
"The Organ Grinders" by Bill Fitzhugh "Good Omens" by Terry Pratchett and Neil Gaiman and anything by Paul Jennings
Recently finished 'Kingdom of Fear' by Hunter S. Thompson. Couldn't help but burts out with laughter in some sections.
Just finished Thompson's classic 'Fear and Loathingin Las Vegas' for the third time. So many funny parts in that book, you forget about the serious undertones!
The first book I ever laughed out loud while reading was George Burns' autobiography, which I believe is called They Still Love Me in Altoona.
Where Have all the Bullets Gone?-Spike Milligan.Almost anything by him.And,Nonsense Novels by Stepthen Leacock.
+The Catcher in the Rye" and "Catch 22" both made me laugh pretty hard. Fear and Loathing did too but it was ruined because I had already seen the movie a bunch of times.
Forrest Gump by Winston Groom. MUCH better than the movie. The funniest part to me was the part about him and Jenny getting it on. Apparantly Forrest really knew how to take care of a lady. THAT part definitely didn't get put in the movie.
The Devil's Dictionary is a good choice (first post). I don't read 'funny' books. But... A Fairy Tale Of New York by Donleavy made me laugh out loud years ago.
For me it would have to be 'the curious case of the dead dog by Mark Haddon. It is written from the perspective of a young boy with autism.