Some of the funniest books I’ve ever read:
Kingsley Amis - Lucky Jim
Charles Dickens - David Copperfield
Jonathan Swift - Gulliver’s Travels
Patrick De Witt - Ablutions
Douglas Coupland - JPod
Sue Townsend - Adrian Mole: From Minor to Major
John Kennedy Toole - A Confederacy of Dunces
So what are the funniest books that YOU’VE read?
PG Wodehouse: Literally any book by PG Wodehouse
The Fist of Fun novelty cash in book
Adrian Mole
Joseph Heller - Catch-22
Bill Bryson - Notes From A Small Island/Neither Here Nor There
Woody Allen - Complete Prose (yeah, I know…)
A Comedy of Errors (in Shakespeare’s tongue).
Another vote for A Confederacy of Dunces and Catch 22…
Ginger Man seconded along with lots of other Donleavy!
Actually all your choices are on the money.
Seconding Catch 22 and Lucky Jim
Also So The Wind Won’t Blow It All Away by Brautigan, very beautiful and bleak at points but the bit where he’s interviewing the hamburger chef practically had me on the floor laughing. Also any of the memories of the fat fishing couple who brought their entire lounge to the lake kept getting funnier every time he went back to it.
Donleavy lives up the road from my family home! 
He’s in his nineties and pretty eccentric. Johnny Depp visited him years ago to talk about making a movie of The Ginger Man but nothing ever came of it
coupland is my all time favourite but j-pod is the first book of his I couldn’t even follow, like it didn’t coalesce in my head as a comprehensible story, might be because it was after the point my attention span atrophied to its current state.
Been a while but I remember thinking Happiness TM by Will Ferguson was pretty funny at the time
BS Johnson - Christie Malry’s Own Double-Entry
anything by Magnus Mills especially Restraint of Beasts
Samuel Beckett
gargantua and pantagruel
three men in a boat
a confederacy of dunces
most jack vance and robert aickman stories
Catch 22 is funny? Shit, I just assumed it was really po-faced and boring! That’s why I never read it!
Everything Is Illuminated - Jonathan Safran Foer*
Under the Net - Iris Murdoch
The Peculiar Memories of Thomas Penman - Bruce Robinson
*until the suckerpunch that left me sobbing myself to sleep one Christmas, lol