No one mentioned Nox yet?
i loved that game! had a pretty unique feel to it in the way you move and cast/attack etc. i seem to remember being impressed with the sparkling cursor at the menu screen too haha. i'm sure i played it again for nostalgia's sake a couple of years back, from what i remembered it aged worse than expected. : (
here are some of the more recent rpgs i've tried:
oblivion - a beautiful, technically impressive sandbox. problem is it's about as interesting as a box of sand. has probably the most impressive mod scene i have come across (besides bg2 ofc) but even that didn't save it for me, i just didn't find the world interesting.
mass effect - i was hugely excited about this game. i did manage to complete it but i pretty much hated it by the time i did. it does have replayability and roleplaying elements, as the way you talk and complete objectives really changes how things pan out. none of this really matters for someone like me though who just didn't enjoy it or like the dialogue. that said, many many people did.
fallout 3 - if you've never played the early fallout games and therefore don't compare it to them then you can have a lot of fun with this one. also has a fairly impressive (and growing every day) mod scene, because there are many people working on mods from both the oldschool fallout scene AND the huge oblivion mod scene. once they have all worked their magic i reckon it could become something special, when i played it though it was only really fun enough to complete once then forget about it.
the witcher - in my opinion probably the best of the more recent rpgs. you cannot choose your character or even name him, but like mass effect you can lvl him and roleplay him how you please and this effects the gameworld, the difference being that the witcher does it in a more interesting, far less cheesey way. some of the quests, particularly the city ones are also pretty interesting and deep too, and will draw you in like the rpgs of old. this is marred somewhat by the obligatory collect X amount of dog teeth and bring to X npc type quests, but you know every rpg has those.
as for the old games:
fallout 1/2 - incredibly unique setting, with some very very impressive dialogue and characters. the most impressive thing though is just the overall atmosphere. everything comes together nicely to create a dark, bizarre vibe unlike any other game. also a very impressive (if somewhat elitist) modding scene. much like baldur's gate 2 there have been people working on unofficial patches and mods for years, so you can play a pretty much bugfree game with almost everything the original designers wanted to put in but ran out of time to do so. that said, the graphics are pretty damn old these days, i don't have a problem with old graphics providing the music and general atmosphere holds up, but many do.
icewind dale 1/2 - the first is very much like a more action/multiplayer version of baldur's gate. far less roleplaying and no joinable npcs. don't let this put you off though, even though it lacks in some areas it makes up for it with atmosphere. some of the music and art is simply beautiful. i'd definitelly give it a try even if it only serves as something to dabble with inbetween baldur's gate 2 playthroughs. icewind dale 2 is pretty much more of the same with the addition of a new ruleset that works more like neverwinter nights. this adds a great deal of depth but with that comes many more hard decisions to make, especially when you're creating more than one character. also worth noting that the main flaw (lack of joinable npcs) can be remedied these days with mods, making them a whole lot more worth your time. if nothing else, you should use the portraits from these games, i usually swap all my baldur's gate npc portraits with ones from the icewind dale series. : P
arcanum: of steamworks and magick obscura - this can definitely be worth your time if you are willing to look past some pretty major flaws. has a huge world to explore with a lot of freedom and a huge amount of quests, all played out in a pretty unique setting (technology vs. magic). the problem is it just feels so unpolished. with the help of some mods you can make it a lot more stable and playable, but even with those it lacks polish and still feels pretty unbalanced. that said, i still enjoyed it greatly, but others on my list come first.
planescape: torment - you MUST play this game. it lags behind baldur's gate 2 in the gameplay department with less customizability and less spells/weapons etc, but where it shines more than anything i've ever played is dialogue. some of the conversations in this are so damn good that they almost feel out of place being in a computer game. this, along with very deep characters, very fitting music and a well designed, weird world make this one unmissable in my book. GET IT.
well, that ended up a lot longer than planned and the op is probably long gone anyway. ah well, gotta love typing nonsense with a morning coffee.