Here's a funny one I found today. Only holds the attention span for a few minutes, but the voiceovers are cute.
http://www.pizzahut.com/summerofcheese/udderchaos.htm
Thanks for all the links, folks! Some great stuff here. Keep 'em coming! I plan to put together a little site with nothing but links to online games (yes I know it's been done but not by ME).