Planescape:Torment might not have anything particularly unique about it's gameplay, but the characters, world, and story are what really makes this game stand out.
In the days of old (1999), when Black Isle Studios ruled the land of RPGs, creating such acclaimed games as Fallout (1997), Fallout 2 (1998), and Icewind Dale (2000), a game was created featuring a world so stupendously unique that it has yet to be revisited with the media of video games. That world was Planescape (which is actually a pen and paper rpg, but we're talking video games here). In this world, a door could be anywhere (a hole in the ground, an archway, or even in a dresser), a key could be anything (a piece of junk, a coin, a knife), and could lead anywhere in the known, and unknown, multiverse.
I mean really, the main character was immortal. How often do you get to be immortal these days? (Lost Odyssey) Hmmm, ok, how often do you get to be a cool immortal? (Kaim was kinda cool) Fine, how often do you get to be an immortal that looks like he's been carved up more than the Christmas goose; that wakes up in a morgue with no memory of who he is; that has a talking skull as a companion; that gets to make out with a tiefling; that gets a githzerai with a sword made out of chaos; that gets a celibate succubus priest on his team; that gets to journey to hell and back, literally, just to find out who the hell he is and why he's immortal? (You wake up in a morgue without a memory in Shadowrun) ...fuck you.
I guess the point I'm getting at is that the world of Planescape should not be forgotten by the gaming and game developing community. That world has infinite potential, and the fact that there is only one videogame using it seems kinda sad to me.
I'll leave you with some words said to me by the night hag Ravel
"What can change the nature of a man?"
(What's a night hag)
*sigh*...goddammit...