The Witcher games, especially the second one, are easily the best on that list.
The first Dragon Age (Origins) is very good as well and Deus Ex: Human Revolution is terrific.
Dark Souls is hard as f***, Mass Effect 1 has massive sidequest and loading time issues, strange visuals and annoying voice acting and the sequel is pretty much a cover-based 3rd person shooter with watered down RPG elements and a run-of-the mill sci-fi plot (continued).
Never played KOTOR games.
Out of those, I'd say The Witcher 1 and 2, followed by Deus Ex and Dragon Age for a tie. One could argue that Deus Ex is just as action oriented as Mass Effect 2 but then again, it never pretended otherwise.







