I partially agree with the previous comments, but I still can't understand why everyone thinks 2 was the best; for me, 3 was better. It was more challenging - the previous games were tediously repetitive and boring (3 was still quite repetitive). The gameplay was almost identical, if not slightly better in 3 - the fighting definitely was (I actually died a few times). The story was slightly better in 2, but they were both essentially find information and kill Templars. However, 3 was based around the events of the revolution, which, for Americans, might be a bit boring - I assume you're taught a lot about it in school, but I really didn't know anything about it, so it was really fascinating to play a game who's story is centered like that - it's one of the reasons I love the series so much.
People complain about 3's story, but it is based around true events, so Ubisoft were tied down a bit. People, also, complain about the free running and how the cities and buildings weren't very good. I can't really see this argument; the free running was almost the same as in the other games and the cities and buildings were based on how they were actually like in that time. Ubisoft have teams of historians working on the games and maps from that time to make them as real to life as possible. If you don't like them then the real people to complain to are the 17th and 18th century architects who designed them. Connor is said to be boring and uncharismatic, which I suppose he is, but I don't think it changed the game drastically. It was an interesting choice of person - an american indian who's lands and people are being disrupted and destroyed, but restrained and contemplative is probably what he'd be.
Also, Beyond Good and Evil was a great game - I'd buy a sequel.