From the New Yorker:
Weird was his specialty—he thought that way, and he drew that way. Wilson was part of a select group of cartoonists who own their style, who deliver on paper what seems to be a good piece of themselves. (…) The work is somehow inseparable from who they are, and that’s part of what makes it so memorable.
I’m not sure where I first saw his work, but it was probably in National Lampoon, since I was buying that occasionally as a teenager, but definitely wouldn’t have been buying the New Yorker or Playboy, the other two magazines that published most of his cartoons. Though, now that I’m thinking about it, he also drew cartoons for F&SF, so maybe that’s where I first saw his stuff. Either way, I’ve always loved his work.
A collection of his F&SF cartoons is available from Comixology, as is a large collection of his Playboy cartoons, both published by Fantagraphics. A couple of other collections, Still Weird and Even Weirder, are available for Kindle, at a pretty low price. I really should pick up one or more of those. I could use a little more Gahan Wilson in my life right now.