SP and MP best the series has even seen
As many have said, the technology for AC is getting a little old but that doesn't mean the game isn't good. I have spent up to this date around 8 hours on the single player campaign and the completion is about 30%. I don't just play the games for story and a game like AC, its fun to wonder around the roof tops and getting into fights. The story so far is amazing and Ezio Auditore Da Firenze will be missed. Not many game developers take the gamers into the world of their main protagonist and have them start playing from the date they were born to the point they get to retire.
As for the multiplayer aspect, if there is one thing i have noticed its the fact that the multiplayer is extremely addicting. I have never been a fan of MP although i have player many. I always preferred SP because of the story games offer. My MP playtime is around 21 hours (that number i believe says a lot on its own) i love playing the MP in this game. The pace of the game is amazing and this is one game i can say that has pulled me into the MP for its simplicity yet exciting gameplay.