Unfortunately, it appears you own every RPG that worth playing. Well, nearly. If you haven't played them already, and if you care for D&D, GOG has all the classics ( Baldur's Gate 1 & 2, Neverwinter Nights ( NWN2 is available on Steam ), Icewind Dale 1 & 2, Fallout 1 & 2, Arcanum, the slightly overrated but still legendary Planescape: Torment, and a lot more ).
On Steam, Risen is pretty good, though far from perfect. If you've ever played Gothic 1, 2 or 3, you'll have an idea of what I mean. It's far better than Gothic 3, though. Of course, Risen 2 is right around the corner, so chances are that'll be a far better experience.
The Witcher 2 ( I realize you only said you weren't interested in games like it, not that you hadn't played it, but ... ) is getting an enhanced edition in two weeks time, which is basically a free expansion, so that'll be good.
Otherwise, I think you've basically discovered what so many others have discovered: there was a time when really good RPGs were released yearly - at least. Now we're lucky if we get a half-decent one a year, with a good one every other.
The same, incidentally, and on a somewhat unrelated note, is true of fantasy RTSs. I recently went looking, and ... they just don't make those anymore. I mean the Warcraft-esque RTS games with base building and all that. It's a real shame if you ask me.