the Phoenix Wright games are actually really really good even though the're almost entirely text based and their really nothing like torment, still I'd recommend them. They can be a bit silly at times but some parts just make you feel so epic and the writings excellent ,fantastic soundtrack too.
heres some other games I'd hold close to the same level as planescape for other reasons like atmosphere,game-play,etc
defiantly Metroid Prime 1(cube version the wii version isn't as good it's missing stuff and the cube one actually has better controls) because it has some of the greatest atmosphere ever and will really immerse you it's also got a great back story and interesting data about all the creatures in the game.(you have to use the scan visor though).here's a review Metroid Prime Video Review - GameCube
System Shock 2 has a pretty good story and great game play it's kind of like a far far superior version bioshock(I didn't like bioshock at all it just felt like a gimped, awful version of system shock). heres a review http://www.youtube.com/watch?v=TLiZ82oP4CM
Demon's souls is the only thing recent that really pulled me in even though it's light on story the world is crafted so well it just makes you want to explore plus the gameplays the best I've experienced in a long time some people find it too hard for them though but I never did. heres a review http://www.youtube.com/watch?v=8kUDZYfBugA&hd=1
the Sam and Max games(the new series and the original) are great at some times but at parts the writing falls a bit short season 2 is quite a bit better than 1 but I'd still recommend playing 1 first even if it feels like your slogging through it just to reach the end at times.sam and max review http://www.youtube.com/watch?v=AuqtyDtk8es
eternal darkness sanity's requiem is pretty cool too and you might like it. It gets a lot better towards the end and has some really cool moments(can't tell you them cause it would ruin it).heres a review for it Eternal Darkness: Sanity's Requiem Video Review - GameCube
I would suggest more but I'm trying not to suggest anything others already have suggested. I also might have missed some games because its 1:00Am and I'm pretty tired