I think the title says it all.
Can’t go wrong with www.liquidgeneration.com.
Great reading over at www.televisionwithoutpity.com
(it is supposed to be a kids website, but it is really surreal and compelling in a yellow submarine sort of way.)
A great one is www.homestarrunner.com
I guess it has to be my type of humor to enjoy it (stupid humor that is)
You mean…without porn? 
Love the time cube.
I spend hours and hours here
I would but you’re already here…
http://www.livejournal.com/community/customers_suck/
Stories about horrible customers. Some funny, some kind of horrifying, some that make you want to smack the people who tell them. Definitely good for lots of time-wasting.