Places you should probably already know about:
Abstruse Goose is good for a laugh.
AD plays some decent Japanese tunes.
Brawl In The Family makes a lot of Kirby jokes.
Bug is frequently hilarious.
Consumerist reports on how you're being screwed.
Freenet is something you should be using - a completely decentralized, encrypted, anonymous P2P storage network on which websites and forums can be hosted, files can be shared, and email can be exchanged.
Hacker News is an interesting feed.
Jul might be a fun place to visit.
Lua - learn it, love it.
Not Always Right shows how wrong the customer can be.
Sinfest is often entertaining, and beautifully drawn.
SMBC tends to amuse.
The Fucking Weather delivers exactly what it promises.
xkcd is an often-brilliant comic with a lot of nerd humour.