Originally Posted by Vuashke
pretty much all the interplay/troika games had great stories. even lionheart had an interesting story, despite the game being kinda boring
Gotta give you credit for listing two of my favorite devs(RIP)... Though it bears mentioning that ToEE, while a great(perhaps one of if not the best) TB RPG, is a far cry from a good story driven game. Troika also produced one of my favorite aRPGs, which coincidentally has/d a good story, Vampire: the Masquerade - Bloodlines(combat - aside from some nifty vamp powers - can be bad; I think some fan made mods and patches have improved it somewhat). Also, Arcanum: Of Steamworks and Magick Obscura is another great Troika title with a solid story(again clunky combat).
Anyhoo, in an attempt to give an original suggestion, I will refrain from repeating any other previously mentioned games...
My vote goes to -> Neverwinter Nights 2: Mask of the Betrayer.
Of course any valid discussion of "best story driven game" is predicated upon what one considers paramount to a story driven game... Games are an interactive medium, thus I believe that an interactive/reactive narrative is key. Ultimately, that means the PC(player character or if you wish "actor") can affect or alter the plot and/or narrative; oh and conversely, the reactive narrative/plot should in some way affect or alter the PC. Player agency constitutes a huge role in an engaging interactive/reactive narrative. Now some people feel the exact opposite, a good example of this would be the game Heavy Rain, which is quite nearly an interactive movie with some minor trappings of game elements. The argument basically boils down to linearity vs nonlinearity, ranging from interactive movie to emergent narrative/gameplay.