#17: Assassin's Creed: Brotherhood (Ubisoft, 2010) - PS3 (also on 360 and PC)
This is where the series was annualized. Many people dismiss Brotherhood as "AC2.5, just an expansion pack". And you know, they're probably right - but I had so much fun with this game, and that's what matters right? In terms of story, I prefer AC2, because there I could see Ezio's full development. Here, he's fully developed, so there's not much to it, but it's still entertaining though. The gameplay adds some things that make the whole game a cakewalk: recruiting assassinis, the crossbow... but personally, I don't play games for a challenge, I play them to have a good time. And a good time I had with this one. I like it as much as AC2, with AC2's plot putting it a liiiiitle higher on the list. However, this game has a GODLY multiplayer. I got to level 50 not because of a trophy, but because I just couldn't stop playing it. It was my favorite competitive multiplayer of the gen BY FAR. Strangely, AC3's multiplayer didn't interest me in the slightest. I couldn't tell you why.
Also, despite all the issues with Unity, I still greatly enjoy this series, despite missing most of them. Here's hoping AC Victory delivers.