Humor:
The Capitol Steps
Editorial Cartoons
Calvin
and Hobbes; advice on life in comic form from Bill Watterson; Calvin and Hobbes mashed with Dune; comic about Calvin as a parent (the strip, called Hobbes and Bacon, is by Pants Are Overrated)
Zits
General Protection Fault
Ubersoft
Itchy Feet
PhD Comics
xkcd
autocorrect fail
Manu's comics
Ok/Cancel
Best of
Craigslist
Tom The Dancing
Bug
The Onion (people who take The Onion seriously)
Other humor mags