www.homestarrunner.com - so funny. the strongbad emails are mega-awesome
www.blindwino.com - a funny guy from the states who may or may not still be maintaining a website for all I know
www.yip.org - unbelievably funny stuff
www.nationallampoon.com - makes me laugh
I considered putting a link to the onion but chances are you've already heard of it and consider me a cheap knock off. So I decided against it.