Microsoft just unveiled another couple games for backwards compatibility, and they are two rock-solid games from Ubisoft in the same series: Splinter Cell: Blacklist and Splinter Cell: Double Agent.
Blacklist was released in 2013, and the narrative is set after the events of Splinter Cell: Conviction. Conviction adds a bunch of new skills and actions that Sam Fisher can pull off, and new items like the Tri-Rotor drone, a compact surveillance drone that spies on enemies, creates distractions, blasts enemies with electric shocks, and self-destructs to kill enemies added some new depth.
Double Agent came out in 2006, and was the game that took the series to the 360. There weren't a lot of new additions to the series with this title, but back in those days, graphical improvement went a long way, and the game was still a completely solid entry into the franchise.
You can just pop your disc in if you already own the titles, or if not, you can go here to check out everything that's available.