Love Carl Hiaasen, esp 'Double Whammy' and 'Lucky You.'
Joe R. Lansdale is the master for me. The Hap Collins and Leonard Pine mysteries leave the majority of other crime/humor novels I have read in the dust.
Lee Goldberg's 'The Man With The Iron On Badge,' is also seriously funny.
Donald Westlake is also funny and entertaining too. I still think Lansdale is the master, though.
It's my genre, too ;-)
Charlie Huston's Hank Thompson trilogy (Caught Stealing, Six Bad Things, and Dangerous Man) gave me a few
laughs, but then I am an unwell person.
The best is a Scottish author Christopher Brookmyre.
All fun and games until someone loses an eye
To Boil a Frog
The Attack of the unsinkable rubber ducks
Quite ugly one morning
Country of the blind
Not the end of the world
A big boy did it and ran away
The sacred art of stealing
Be my enemy
One fine day in the middle of the night
A snow ball in hell
I like Donald Westlake's 'Dortmunder' novels. - A gang of 'working thieves' and bunglers who have a lot of funny mishaps. - Many of Elmore Leonards books are very humorous too, I loved 'Maximum Bob' and 'Get Shorty' in particular.
I inevitably go back to one of these kind of books after 5-6 thrillers, I find a bit of difference helps getting in a rut.
May I offer up my own short story series? Maynard Soloman is a profane and clueless private investigator solving 21st Century problems with a 1930s vocabulary. Most recent installment is "Maynard Soloman & The Job-Nabbin' Illegal Immigrants."
If we're talkin' novels, though, I don't think I've read an Elmore Leonard work and not found something humorous. "Up In Honey's Room," for all its serious plots about Nazis and killing President Truman, is full of comedy.