I’d actually recommend Puzzle Quest. I know it’s technically a match three game, but the combat system works really well, with a suprising amount of strategy. Then again, due to it’s casual nature it may not be your cup of tea.

I see Baldur’s Gate was already mentioned, and as a semi-companion piece the Icewind Dale series is pretty good. It’s much more combat orientated than it’s brother though, and it can be somewhat frustrating.

Also, I remember having fun with the shareware Exile/Avernum series, but looking at the website, the full versions seem a tad expensive, and I’m not sure how well they hold up now.

Good luck finding something!