I've always loved Neverwinter Nights (original and 2), mainly for my love of 3.5 D&D. Other than that, Morrowind/Oblivion is good. If you want a good old-fashioned dungeon crawl, I'd suggest picking up an old copy of Baldur's Gate: Dark Alliance. Then again, if you like your free-roaming worlds, the original Baldur's Gate was great, albeit pretty outdated in terms of graphics today. Then there's always Fable 2.
Of course, you could always go out and start learning D&D. It's one of the best RPGs around. I'd suggest buying the old 3.5 rules, but 4E is much more simple. Your choice.
EDIT: Also, search for Thy Dungeonman.
Ye can't get ye flask.