FarSide is a cartoon series by GaryLarson. Some people find it hilarious, some find it occasionally amusing, some "just don't get it", and some find it downright offensive.
Also available on video. http://www.thefarside.com/
Oh yes, and he thinks cows are fundamentally funny. Not sure what he thinks of CowOrkers.
One of our guys has what I will call a "FarSide/Dilbert fusion" piece on his wall.
It's a FarSide panel of Hell, with a coffee urn and a line of people getting coffee, and one of them remarks, "The coffee's cold. They've thought of everything!"