Assassin's Creed 3: 9 out of 10
It's the best one yet as far as gameplay, setting, and graphics, and the ancestor story is the best one IMO so far as well. I love the Revolutionary America setting. It's very, very, very good, and really sucked me in. The cities are so different than the ones from previous AC games, which is a very good thing. The wilderness and being able to hunt is really cool, though I wish there were more animal types to hunt.
Now, the present day stuff with Desmond isn't terrible, but it isn't particularly good either. The ending isn't very good, mainly because it is way too abrupt considering it was built up for 5 games. They seemed more focused on setting up another game than giving players a gratifying conclusion. That's a very small part of the game though, as with every other AC game. The majority of the game is spent playing as Connor in the past, and that is as good as any other AC game, better IMO.
The glitches are a little much, and might make some people hate parts of the game. I didn't mind them that much, but the game could have used another couple of months of work to get rid of those problems.
Highly recommend the game to anyone interested in the series, even if you've never played an AC game. It's different enough from the others that it is a good starting point, with the best gameplay and setting.