As guessed by Player2:
11. Mass Effect 3 (PC, also on 360, WiiU & PS3)
The end of an epic trilogy by Bioware. Mass Effect 3 tried to take all the elements from the previous two games and bring them together into a single, epic package. For the most part, they suceeded. The gameplay was further refined from ME2, the RPG elements were back but without the arduous item lists from ME1 and the story (for the most part) is rounded off nicely with the majority of story arcs completed over the course of the game. During the game, you effectively seal alliances between previous political enemies, explore the nature of life through AI/Geth characters and solidify or destroy all the relationships made in the previous games. Everything seems to work very well.
It's unfortunate that the final ending was such an anti-climax. Having said that, I don't think the ending was anywhere near as bad as the controversy it caused suggests. The original endings were sparse but left you with enough material to figure a few things out. I think some credit should be given to Bioware for listening to criticism and releasing a new ending that took more of the players decisions into account and expanded on the sparse details in the orginals. I doubt many other developers would have done this.
This was also the first game in the series to introduce a multiplayer element which works surprisingly well. Not the most varied multiplayer mode, but still a lot of fun. The mix of different abilities, racial traits and weaponry make for an incredibly enjoyable experience. Biotic Charges followed by Krogan headbutts and blasts from a shotgun... so much fun! The only down side is that they obviously re-used multiplayer maps for what are probably the worst side quests in the series. The side quests in general actually, whilst vast in number, aren't up to the same quality as in ME2.
Overall though, the game is a good way to round off what has been an incredibly ambitious series.
