I’m sure everyone has already been to these sites before but anyway:

For the unhinged.

The One, The Only… Fark!
Hey look! Its Something Awful! This site is hilarious
Satire anyone? The Onion
I smashed my house up with a bat.
Its Meat. Its Red. Its Red Meat.

For the geeks.

Nearly as good as the print version but without the ads, New Scientist.
Interesting daily tech news for geeks etc, Wired.
Check this out. What did your favourite site look like in 1990? Archive.Org
Good game dev site, Flipcode
Another one, GameDev.Net

For the musicians.

Drum and Bass all over the place. Spinwarp.
Good music production forums. Sample City.