I want to mention briefly the kinds of written humor I find most amusing. My all-time favorites are Robert Benchley, S.J. Perelman, Groucho Marx and Garrison Keillor. Note that there is not a belly-laugh in the bunch. For some reason Art Buchwald and Dave Barry leave me cold. Benchley, Perelman and Marx loved to play with the language and use unusual vocabulary for comic effect. And Keillor, in writing as in spoken performances, has this gentle buildup to absurdity that just rocks my world. It is hard to explain, and I shudder to think what my taste in humor says about me, but there you are. (You may enjoy my My Prairie Home Companion Script, if you know the show).
Last, but not least, I find Andy Borowitz (of the Borowitz report in the New Yorker) to be uniformly hilarious―like the Onion but with taste and wit.