lasagnacat has some of the funniest videos on Youtube, hands down.

More:
08/18/1978, 01/05/2005, 10/26/2007, 02/24/2006, 04/25/1979, 03/24/1979 , 06/15/2007, 05/22/1980, 02/03/1991, 01/26/1995, 06/01/1982, 05/14/1979