Ryan North's The best of Dinosaur Comics: 2003-2005 A.D. had me howling with laughter and passing the book around to whomever I could lay hands on to point out particularly good strips.
Dinosaur Comics is an unlikely gem of a webcomic -- the same six panels every week featuring three dinosaurs and a house, a car and a woman in danger of being smushed. What changes from strip to strip is the dialog, and man, there's a lot of it.
This is a wordy comic. The jokes are often erudite, sometimes just plain goofy. The creator, Ryan North, is mining this odd little visual vein and coming up with a seemingly bottomless well of extremely funny material. Some of it relies on the visuals, some would work nearly as well as text.
Every now and again, Satan appears and drones on about his favorite video games. Then the T-Rex will explore (in his charming, naive way), philosophy and religion. Then there's a strip about polyamory. Then several strips about etymology and word choices. Funny jokes about comic books. Then God appears and T-Rex is the only one who can hear him. Then cuttlefish move in next door and behave in a threatening manner. Fan-culture and the canon make an appearance. And so on.
This strip is so improbable, so unconventional -- and so wonderful. It's like a distillation of the funniest stuff on the web, improbably combined with clip art, unapologetically weird and interesting and fantastic.