There are some excellent U.S. political cartoonists on the web. Some of my favourites are Ted Rall, Pat Oliphant, Ben Sargent, Tom Toles, Clay Bennett (beautiful, amazing work), Tony Auth, Bill Deore etc.
Today I discovered David Rees to throw into that mix. It makes me think of what things like Dilbert should be, if only Dilbert wasn't so lame. But the humour has something of Herbert Kornfeld about it before The Onion decided it was in their best interests to shut off access to their archives. If you're a fan of Herbert's, there even appears to be a Letter-Opener-Of-Death in some of the panels.