Of all time? Probably the 2004 E3 trailer of Zelda Twilight Princess for the synchronized orgasm of the crowd alone.
Recently I'd have to say The Last Guardian. It makes me happy to watch but sad at the same time cause I feel the end will be someone/thing dying AKA the big cute griffin-dog.
Other good ones include SMG2 at E3 2009, the white engine trailer showing off the FFVII intro, and Metroid Other M made me jump up with excitement.
Speaking of badass metroid videos there's also this commercial for Metroid Prime 2 that I thought was awesome.
MaxwellGT2000 - "Does the amount of times you beat it count towards how hardcore you are?"
Wii Friend Code - 5882 9717 7391 0918 (PM me if you add me), PSN - MaxwellGT2000, XBL - BlkKniteCecil, MaxwellGT2000
