Since this thread has popped up, a few new games have been added.
Most notably, there's Neverwinter Nights, a game I hated when it was first released but that I've really come to enjoy.
As a single-player RPG it's incredibly disappointing, but as a multiplayer RPG it has yet to be surpassed.
What it took for me to enjoy it was a paradigm shift: Realizing that the game is not a CRPG in the traditional sense, but rather that it's a D&D emulator for PC. The adventures released with it are not "the game," they are sample campaigns provided by the devs.
But all in all, I think NWN was meant to be played with multiple other people, one of whom is a DM.
The other big game is... Civ V. Yes, I know. No, I haven't gone and switched sides. However, I find that G&K, while still not nearly as enjoyable as Civ IV, is nonetheless a very fun game. I would rank it at around the same level as Civ III - not the best the series has to offer, but still worth playing.
I've also been getting big into oldschool RPGs. Picked up Ultima VII not too long ago, and I've realized that as far as first-person party-based RPGs go, Might and Magic IV+V are king. Man those games are fun.
I've also got a ton of games that I picked up on GOG sales but have yet to install and start playing. Panzer General II and Imperialism II are the two big ones right now.