Final Fantasy XIII-2. I'm on a sidequest in chapter 1, so it's already better than the original! Random Encounters are back too, along with semi-conventional levelling (crystarium still exists). Seriously, if they made the first 13 like this it would be twice as good.
The story isn't so bad either. Sure you're looking for your lost sister or whatever, but the fact that you see that sister fighting some dude (the purple haired guy in the trailer) at the beginning really does place wonder in the brain. Plus - Time Travel! And for any collectors out there, there are 160 "Fragments" to collect by doing main and sidequests....yay! MILES better.
Oh, and the music is cool too. You have the regular track playing on a level, and when something called a "Mog Clock" (a random encounter with a monster, but the clock gives you a timer for a pre-emp strike) comes up, it's plays a disco-ish version of the song! For the first level, I just paused the game on the disco version and listened to it! Seriously good purchase, because it was between this and MGS HD.