Modern ones are kind of hard to quote, but I will try to remember some.
-I liked the TES series, Daggerfall being my fav, but Morrowind is also a good pick.
-Darklands can be good, but has some horrible flaws.
-Realms of Akania 2 - Startrail was near perfect, plus it is often described as an adventuring simulator instead of a rpg. The problem with it would be that you can't really play without a manual, the ingame help isn't so good and you can get easily messed up. I can tell much about the followup as when I bought it, my cd came fuxored up and I couldn't get past some points. That reminds me I should download it somewhere and play it when I have time.
-Future Magic and Hard Nova, very very old school rpg games, but it was fun when I was young.
-Wasteland, while we're talking about oldies. This made my days when I was 12.
-Most of SSI's D&D games, such as Eye of the Beholder, Champions of Krynn, Pool of Radiance, Al-Qadim, Forgotten realms, Menzoberranzan, etc. Yes, there are a -lot- of them and I recommend them all, specially Dark Sun.
-Albion, besides the 3D bits giving me a headache, it was great.
-Jagged Alliance, if it can be considered a RPG, if it can, include X-com. I mean, they're more like strategy/tactics games with RPG elements.
-System Shock 2, shooter with RPG elements if that's allowed in the list too, if so, include Deus Ex. And what makes Deus Ex different from Mass Effect? Well, in Deus Ex your skills made a difference in the sense you could solve things differently based on your skills, in Mass Effect you pretty much just kill everything in the way.
-Arx Fatalis, love & hate relationship with this one.
-Neverwinter Nights, only the first one. The modding and near-by-the-book D&D made it great. I played it for several years online and bought every expansion.
And then we had this 6 years blank without a complex rpgs released. That's ignoring oblivion and fallout 3 of course, not to say they weren't good, but they were simplified compared with their predecessors. I never managed to finish Oblivion as it annoyed me to tears at points and by the point they had mods that fixed those issues, i couldn't touch it anymore. I might some day, but I play daggerfall every other month, so it's kind of hard to not compare both and feel bleh at Oblivion. Fallout 3 suffered from a similar issue but thanks to modding, I've playing it lately and it has been actually fun. It's sort of interesting how it's acceptable to see someone's brains and eyes blown out, but they removed the more mature events from fallout, such as fucking mother, then daughter, then killing their husband/father as a quest.
So there you have it. 6 years without good rpgs, if you ignore the modding community.