Mine is "wat?" It mostly occurs on the 2+2 forum, and it cracks me up every time. [ ] one page thread [X] multiple page thread
and the epic reply: Explained here: http://knowyourmeme.com/memes/how-is-babby-formed <object width="480" height="385"><param name="movie" value="http://www.youtube.com/v/Ll-lia-FEIY&hl=en_US&fs=1&"></param><param name="allowFullScreen" value="true"></param><param name="allowscriptaccess" value="always"></param><embed src="http://www.youtube.com/v/Ll-lia-FEIY&hl=en_US&fs=1&" type="application/x-shockwave-flash" allowscriptaccess="always" allowfullscreen="true" width="480" height="385"></embed></object>
Socially awkward penguin is probably the funniest picture thingy out of the bunch of raptor, wolf, dog, etc http://austin.craigslist.org/bik/1681239789.html
Cool thing about that, is you can substitute "clutchfans down" with anything else, and it still works.