For me it has to be Sinfest, although there may be a better one out there. I just have to find it. Here's one of my favorite strips. If you find a funnier site or strip, post it up; I'm up for a good laugh.
*Oh yea, BTW, the following strip may contain some vulgar language. By feasting your eyes this piece, you shall not hold any reparations over me may it be emotional or physical such as your sides spliting. Enjoy!
http://sinfest.net/comics/sf20000901.gif