Basically, what the title says.

My favorite to date has to be the Vet and the n00b from Call of Duty, Modern Warfare 3 - http://www.youtube.com/watch?v=zuzaxlddWbk

So - what's your favorite vids ... just remember they have to be adverts, not just in-game footage or a review.

I really like this one http://www.youtube.com/watch?v=Zo5-XpQ5Jkk
Freddiew's advert for Battlefield 3 (Also a good game)