As a full package I'm giving this to 7, hands down. 5 minutes in you've hijacked a train, killed some soldiers, and set a bomb to blow up a giant reactor. Then you fight a robot scorpion.

I'll give second place to X.
X because it lines out exactly where Tidus and the world stand in a few minutes. It shows off Tidus's skills and makes it very clear that he's a pro athlete, not just some random guy who is magically strong enough to fight monsters. It lays out how rich and prosperous Zanarkand is. And then it blows everything up with the introduction of the world manipulating, gigantic and destructive Sin.

Honorable mention goes to Crisis Core
Crisis Core for the sole reason that it shows off exactly what a Soldier 1st class is capable of in a way 7 couldn't because of the limited tech. Barret being impressed by Cloud is a lot more when you realize what kind of stuff SOLDIER is actually capable of.