JRPGs tell the best stories you can find in any medium, and Xenogears specifically is the very best the genre (and storytelling of any medium) has to offer.
It explores the philosophical ideas of Friedrich Nietzsche, Sigmund Freud, Carl Jung and Jacques Lacan, it delves into the nature of God, The Universe and existence, the nature of human memory, the struggle between man and machine, the horrors of war, ethics, politics, economics... the list goes on, and it does so with such detail and scope.
But beyond that it's quite simply just far more complex (complicated subject matter, complicated narrative, so much shrouded in mystery and ambiguity, with plot twists that make you question everything you had been lead to believe about the game's story) and compelling (helped considerably by its phenomenal music, as well as the fact that it touches on just about every single emotion of the player) than Planescape: Torment, and the same's also the case with Chrono Trigger, Chrono Cross, Radical Dreamers, and the Xenosaga series.
Where do I start? First off, when it comes to storytelling, games aren't even in the same realm as film or literature and I'd argue that JRPGs are pretty low on the totem pole compared to some of the better games out there. Why? It's because they try to be movies. Just as film initially tried to be theatre, people didn't know how to use the medium to its fullest extent right off the bat and therefore imitated its most similar predecessor. In games, this is even more true and makes for poorer storytelling elements because games, unlike cinema or theatre, are offering an entirely new element: interactivity. Some people consider this a plus but when it comes to conventional storytelling, it is absolutely a negative (and JRPGs play to the strictest storytelling conventions). If a game tries to tell a story like a movie, it falls to pieces. Pacing is destroyed by the added interactivity. Say you're coming fresh off a cutscene (ugh, cutscenes)... the next ten minutes may involve you not understanding your next objective and wandering around aimlessly. In doing so, you've destroyed the main story and its pacing. Say you do a minor side quest that does nothing other than gives you a new sword... same thing. Pacing destroyed. On top of that, different regions of the brain handle viewing versus interaction. Jolting the player out of one scenario and into another (and going back and forth repeatedly) ruins the emotional experience felt within the player after a story element has completed. In the end, it turns into a mess where story is packed into 2 hours out of a 30 hour experience, with the player/viewer spending the vast majority of their time doing completely non-story portions of the game. Under the static premise of linear storytelling, this combination of player passive time versus participation time will ALWAYS hinder games and make them an inferior method of storytelling to film, theatre, and literature.
As for Xeno touching on all those philosophical ideas, that's just rubbish. If anything, that HURTS the game's storytelling. Did Shakespeare throw 14 major themes into Hamlet? No, because it creates a giant mess where no theme is explored in detail (contrary to what you may believe) and leaves the audience wondering "what the fuck is going on here?" and not in a good way. How on Earth is it a plus that Xeno spent time touching on themes from five different philosophers who have very different world outlooks? What kind of consistency can be found in that mess? It's a major a problem I see with many anime and JRPGs and I call it "let's throw everything at the wall and see what sticks". Instead of attacking one major theme, the developers muddy the water by loosely touching on several themes and the piece comes out feeling like a contradictory, convoluted pile of shit. BioShock, while definitely a flawed story and game, did a far better job of directly going after Objectivism and working a lack of choice into its gameplay than most JRPGs I've seen. And don't take that as praise for BioShock because I think it's still a bloody mess for its own reasons.
Games will never rival other forms of media in linear storytelling because of their interactivity. The future of game storytelling lies in overarching emotional bonds to characters and the environment, not in trying to compete with film on a narrative basis. An example of where games may be going is Mass Effect 2. I've talked to about a dozen people who I consider to be reasonably intelligent about how they felt during Mass Effect 2. Invariably, they end up talking about the characters. Which ones they loved and took on missions, which ones they left out, and how they felt if that character died. Almost NO ONE mentioned the story elements of the game, which I found incredibly fascinating. If more developers start taking this kind of approach, we could see games rival other media on an emotional basis but the "storytelling" will use games' strengthes as an advantage instead of trying to be a movie and failing. One of the side effects of this form of storytelling is that conventional quest-based stories will lessen in importance in favor of broad-sweeping emotional involvement of the player as he or she makes choices that define their game world. Which takes them FARTHER from JRPGs and shows just how foolish it is that Japanese developers have continued to toil under this form of movie-inspired storytelling when the medium just doesn't work well under those limitations. (Disclaimer: Mass Effect 2 is still a flawed game and has weaknesses that bother me, such as the "white versus black" dialogue choices but the game shows real potential about where the medium can go in the future.)
With that said, there are still many JRPGs I play and enjoy, I just realize that they're quickly becoming a relic of gaming's juvenile past. Of course, there's always time for a developer to step in and do something completely different with the genre and modernize it.
You guys didn't really think I'd be able to leave this thread alone, did you?