Here's another one that wasn't mentioned yet: Alpha Protocol. The game combines Mass Effect gameplay with modern, espionage setting. The non-linear story construction gives the possibility to make a lot of choices that have consequences. The game was formerly available on Steam, but was withdrawn due to music copyright issues. Bringing it back to sale would mean re-licensing some of the songs. Looks like it's not worth the hassle for the publisher. Right now you can buy a Steam key from some resellers. Some of them have shady reputation and the price is over the roof. Thankfully I still have a physical copy of the game.