Jack Handey's short stuff is probably his most famous work, but he also wrote a novel called The Stench of Honolulu.
John Swartzwelder is another comedy legend, he wrote nearly 60 episodes of The Simpsons, and he has a series of detective-pastiche novels (maybe novellas), starting with The Time Machine Did It.
I like these books and think they're along the same lines as Pratchett and Adams, but they are distinctly sillier.
I just started re-reading Neuromancer by William Gibson, and I might start reading The City We Became by N.K. Jemisin alongside it.