Witcher 2 here (in the middle of replaying them all, leading up to a NG+ Witcher 3. The latter is, I think, the best single person game I've ever played. Original Everquest will always hold the title for best multiplayer, simply because at that stage of life I had loads of time to pour into it and was a relatively hard core raider).
Also, intermittently, swtor.
I also have the new Deus Ex in the queue but haven't tried it yet.
In general I prefer RPG style games with decent story.