Which is the best assassin creed uncharted or infamous

Personally I'd go for Infamous - Assassin's Creed didn't really do it for me. Uncharted 2 is better in terms of physics and graphics than the first Infamous, but having played the demo for Infamous 2 I can say that it's been vastly improved in these terms.
If you're on PSN, download the first for free when the welcome back content goes up, and buy the sequel if you like it