Final Fantasy X - Not the flashforward/back to the Zanarkand Ruins, but the actual opening cutscene from Zanarkand with the Blaitzball and Auron and Sin and Otherworld playing. From that moment, I knew the game would be awesome, and I wasn't disappointed.
For me it's between Onimusha 3, (It'd be Oni 2 if it weren't for that dumb theater part introducing the characters) and Nier; not the opening that plays when you boot the game, but the one that plays when you actually start the game:
Snow in Summer is one of the best tracks in the game and the way it builds up through the battle is amazing. By the way I would warn anyone that is currently playing or that plans to play Nier not to follow that link, the recommended videos at the side have a spoiler in them.
I like games with anime style openings fine but they're just far too generic to be considered the best.
Garrus is the Greatest bro in gaming. Devil May Cry 2 is the best 3rd person shooter ever made.