I still like MGS4 over it, just purely because the Metal Gear world is just massive beyond all reality. Not saying Uncharted 2 is bad at all, because it's right up there as being in my top 2 games. I love the ending, as it's hilariously ironic. It had a great pacing for most of the game, mixing up some stealth with heavy action, with climbing and such. It's also magnificently beautiful and really shows the time that Naughty Dog have put in.
To boot, the Multiplayer is pretty fun, especially the Co-Op modes where you re-live pseudo-story situations (tweaked to work with 3 characters), along with just standard Deathmatch, or my personal favourite of Elimination.