Supply Side Jesus Comics. Penentrating satire by Al Franken and Don Simpson.
Mark Fiore does some amazing political flash cartoons. Examples: His parody of Tom Delay, Taxcuts, CNN at War Parodies, a hilarious Anti-gay Superheroes, Media Consolidation, Total Information Awareness, and a pointed Remember 9-11.
Up to now I used to think that Tom Tomorrow was the only decent political cartoonist around. But now there are many.