I thought the Resistance 2 trailer was amazing. Did I like the game? No. But that trailer gave me chills the first time I saw it.
http://www.youtube.com/watch?v=yYyjV2aaOK8
Halo has had a long, proud history of making trailers better than their games. Looking at this commercial, you could be forgiven for thinking that Halo 3 wasn't terrible. If you knew nothing about Halo (all 2 people) than you may even make the mitake of thinking it would have atleast an iota of depth to it.
http://www.youtube.com/watch?v=yYyjV2aaOK8
Seriously, if Microsoft had just let these guys market their Xbox1 then maybe they could have fooled some people into actually buying it.
Of course I have to include my favourite game of all time.
http://www.youtube.com/watch?v=NnKljCh0w54