Having played Uncharted and Assassins Creed (both finished last weekend), I would say that they are both worth a purchase, although it is probably best simply to rent Uncharted first and you can easily play it through in a few days, although personally it is a game that I can see myself dipping into every now and again, although YOU WILL DIE A LOT. It also has one of the best kept secrets ever, but I don't want to ruin it for you. As for Assassins Creed I really enjoyed the sci-fi element cause I like all the theorisising and stuff, and then for the actual gameplay, I loved being able to run around the city exploring, climbing everything, and it is a very non-linear game, completely opposite of Uncharted. To be honest, it just depends whether you like duck and cover games, or hack n'slash, cause they both have platforming although there is more in Assassins Creed.
They both have their flaws, Assassins Creed (only like 1 glitch in the entire game, where a guard got stuck on a rooftop, but that was quite funny, with the patch and 1 short framerate issue, although there were small slip ups that you would have to be looking for to find) has very lengthy cut scenes, and the story does not make much sense till the end. Uncharted is short, you die to often, there are a few plot holes and too many waves of enemies.
Personally, I only own Uncharted, and I borrowed AC of a friend, but AC is not that much longer than Uncharted (10-15 hours probably for AC, 8-12 for Uncharted depending of difficulty) which is my only real cricism of the game.
Personally, I am happy with CoD 4 'till the end of the year, and by then the Omega pack will have got me back to Warhawk, so I'm not sure whether it is worth getting Unreal Tournament III







