For short stories I’d recommend any of the Vinyl Cafe books by Stuart McLean.
The books are stories that were told on his radio show (and you can get them on CD) but are just as funny when read.
Nonfiction:
A Girl Named Zippy: Growing Up Small in Mooreland Indiana by Haven Kimmel
Avoiding Prison and Other Noble Vacation Goals: Adventures in Love and Danger by Wendy Dale
Believe it or not, there are parts of The Pickwick Papers by Charles Dickens that are tears-rolling-from-your-eyes funny, especially when Samuel Weller shows up.
Besides, it’s all classic-ey and stuff like that there.
I read The Liar & there are LOL moments. I would say you have to like British humor to love it - but most folks with a sense of humor will *like *it.
I agree with Catch 22 and anything by Bill Bryson, although I notice viewpoints on Mr. Bryson are pretty polarized here on Dope. Personally, I find him hilarious.
I’d like to recommend:
A Confederacy of Dunces by John Kennedy Toole. This novel is particularly amazing in that it was published posthumously as his only novel and ended up winning the Pulitzer Prize.
The Fan Man by William Kotzwinkle.
This novel spawned a running dialog amongst my friends for years. Everyone I know who has read it loves the book. Appallingly enough, I bear a remarkable resemblance to the Fan Man, in lifestyle, if not appearance.
Just in time for Super Bowl XLII – A Fan’s Notes by Frederick Exley [“Fred Ex”?]
The semiautobiographical triumphs and tribulations (with the emphasis on the latter) of an eccentric, struggling Giants fan.
That would be Pat Tanner aka Patrick Dennis . Great stuff that. I would also recommend the sequel “Around The World With Auntie Mame” and "Little Me: The Intimate Memoirs of that Great Star of Stage, Screen and Television, Belle Poitrine ". Both are quick reads and very funny social satires.
He also penned several other comedic novels under the name Virginia Rowans.
I find your 2 specific recommendations amusing as they follow your observation that folks differ as to Bryson! Or do you want me to express my opinion yet again as to the merits (or lack thereof) of Confederacy. 
Don’t think I’ve ever posted about Kotzwinkle. Don’t know that I’d recommend his work tho. Was at least able to slog through to the end of Fan Man. As opposed to - say - Dr. Rat - which was (IMO) unreadable. And if I thought I bore the slightest resemblence to TFM, I’d aggressively be seeking ways to change myself.
I find it interesting, how difficult it is to generalize about humor. Seems it would be far easier to get agreement as to what is a good drama for example. Whereas folks seem more liable to be more extreme and idiosyncratic in their responses to comedy.
For Kotzwinkle, I’d recommend The Midnight Examiner rather than The Fan Man - great fun, based around the staff of a failing newspaper and the quirky characters who post those weird little ads for bizarre services and products at the back…
It’s my absolute favorite novel, and I think I got it – it certainly was laugh out funny at times, and laugh-in funny at all others.
I came into the thread to recommend Moore. Lamb, however, is both funny and poignant because, after all, we know how the main part of the story turns out.
Does it count if they don’t stay dead / abused? Not naming names but there’s something mentioned somewhere in this thread where the victim(s) don’t stay that way (and no, I’m not talking about Biff’s buddy in the Moore book).
“The Kings of Infinite Space” is a very humorous book, but it also has a love story and an amusing horror angle. Probably the best fiction I have read in a few years.
The kings of Infinite Space
“The Confederacy of Dunces” is a classic, sadly the terribly funny author committed suicide before publishing again. It’s about a very odd person and the jobs he lands in New Orleans.
Dunces
I read about ¾ of “Moo” while on vacation (had to leave it behind). It’s a very funny page turned about college in the Midwest.
Moo
Try Generation X, by Douglas Coupland – body count of zero, IIRC. (Some of Coupland’s novels do include killings but the focus is never on the violence.)
I recently went through a patch of academic work that needed to be balanced out by something truly fluffy and humorous. I found that A Year in the Merde fit the bill nicely.
Oooooh, sounds intriging. Which one to start out with?
If you’re a sports fan, Dan Jenkins is enjoyable. I particularly like Semi-Tough and You Gotta Play Hurt.
Donald Westlake is the undisputed master of the comic caper, especially the Dortmunder novels.
Lawrence Block’s Burglar novels are also favorites of mine.
I also laughed out loud reading PS, Your Cat Is Dead by James Kirkwood, Jr.
The funniest book I’ve ever read: Round Ireland With a Fridge.
I’d forgotten about the guy with the fridge! Funny!
And old favorite I wish I could read again for the first time:
All Creatures Great and Small – set in Yorkshire in the 1930’s
If neither of you are familiar with it, be prepared to have parts of it read aloud to you.
Nick Hornby’s “About a Boy” and “High Fidelity,” but probably not “A Long Way Down.”