Duke Ellington.
The Avett Brothers, The Bad Plus, The Bears, The Beatles, Bela Fleck and the Flecktones, Adrian Belew, Andrew Bird, The Black Crowes, Charles Brown, BR-549, Cake, Camper Van Beethoven, Col. Bruce Hampton and the Aquarium Rescue Unit, Ry Cooder, Elvis Costello, Jerry Douglas, Drive-By Truckers, Steve Earle, Duke Ellington, Bill Frisell, James Hunter, Johnny Griffin, Mike Keneally, King Crimson, David Lindley, Little Walter, Los Lobos, Gustav Mahler, Edgar Meyer, Charles Mingus, Thelonious Monk, Ennio Morricone, Moxy Fruvous, Negativland, John Oswald (Plunderphonics), Ozomatli, Parliament, Phish, Pink Floyd (with Roger Waters), Allan Sherman, Horace Silver, Spoon, Steely Dan (without Owen Wilson), They Might Be Giants, Richard Thompson, Van Morrison, Townes Van Zant, Ween, The Who, Frank Zappa, to name but a few.
Mr. Show with Bob and David (the greatest American comedy show ever created), Ernie Kovacs Show, Monty Python (THE greatest comedy show ever created), Father Ted, Red Dwarf, Good Eats, The Sopranos, Later with Jools Holland, TV Funhouse (both the SNL segment and the short-lived Comedy Central series), Late Night with Conan O'Brien, Night Music with David Sanborn. I also enjoy standup comedians, including Bill Hicks, David Cross, Doug Benson, Demitri Martin, Zach Galifinakis, Patton Oswalt and Brian Posehn.
Too many to mention, though I read everything by Bill Griffith (Zippy the Pinhead). I used to be able to say that about Vonnegut, but I've not read anything he's written since "Timequake", which covers almost all his work.