Wow, nice list, Alaric.
Mine would be pretty similar, so I won't bother writing them here again... though I haven't played as many MMOs or betas as you have.
More games from me:
Dwarf Fortress (Best. Game. Ever.)
Vampire: The Masquerade - Bloodlines
Fable: The Lost Chapters
Fable 2
Fable 3
Ultima Online
Gothic 2
Gothic 3
Arcania - Gothic 4
Might and Magic 3 (not Heroes of might and magic. This one's a dungeon crawler, and a really hard one at that)
The Final Fantasy Legend
Final Fantasy Mystic Quest
Final Fantasy 4
Final Fantasy 5
Final Fantasy 6
Final Fantasy 7
Final Fantasy 9 (skipped 8 'cause it was so bad, never played 10 or above)
Chrono Trigger
Tactics Ogre (dunno if it counts as rpg, one of my all time favorites)
Ogre Battle
Breath of Fire
7th Saga
Avadon: The Black Fortress
Avernum 1
Avernum 2
Avernum 3
Avernum 4
Avernum 5
Avernum 6
Blades of Avernum (played all Avernum games, but never finished any... sad, I know)
Mother 1
Earthbound
Mother 3
Dungeon Lords (which is nearly unplayable thanks to bugs)
Enclave
NetHack
Adom
Dungeon Crawl
and bunch of other roguelikes...
Mount&Blade
Mount&Blade: Warband
ShadowFlare (pretty good Diablo clone imo)
Arcanum
More Ultima games (like underworld, 6, 7, etc)
Slaves to Armok: God of Blood
Divine Divinity
Beyond Divinity
Divinity 2
Oh, and that one series starting with letter M... Diablo-ish style, circa 2002 I think.
Then I remember this one rpg... also from early 2000. Overhead view, very traditional style. You could choose name and type of your starting weapon, and it would level up with your character. I believe it had something to do with dragons, too...
Some of them more obscure than others... you guys played any of those?
EDIT: added more games... OH and btw this should be in General and not Game Discussion guys.