Lately I've been doing a lot of surfing on various sites that have a lot of humor. Ever heard of www.cracked.com ? Man there's some funny shit there. Like this article Right Here.
Another good one is www.verydemotivational.com . VeryDemotivational is another one of those sites with lots of humor for people to slack off at work with. Lots of funny articles and some times some interesting facts as well.
Check out This List for some good times. Be warned, I'm not responsible for non-stop laughter that may erupt in your office nor will it be my fault when you get fired because of porn pop-ups. 
www.bobshouseofvideogames.com <-------- Great Site for Video Game Humor
www.icanhascheezburger.com
www.somuchpun.com
A lot of these sites are on what's called the Cheezburger Network. The next link is a listing of sites all on the network. I haven't really noticed any pop-ups or back-door hack attempts or anything. Just a bunch of good laughs, photoshop fun, and hot chicks in costumes. Check out THIS LIST: http://cheezburger.com/sites
Go Tiger!!! Faster!!!! That chick right there is what is known in the Animal Community as Meals on Wheels...LoL.
Then of course we get photo goodness like this tasty morsel below...
Yeah, me too....hehehe.
