This one’s a classic, rather surprised it’s not already on here:
[video]http://www.youtube.com/watch?feature=player_detailpage&v=y8AWFf7EAc4#t=16s[/video]
Here’s a rather left field one I never thought I would post:
[video]http://www.youtube.com/watch?feature=player_detailpage&v=jqpAgMxhx30#t=4s[/video]