There’s always Diablo 1.

But my favorite is Arcanum: Of Steamworks and Magick Obscura, which was made by some of the people who created Fallout and has a LOT in common with it. It’s an open world, a combination of classic fantasy with elves, dwarves, and halflings with a rising steampunk technology that competes with magic. There are many schools of magic and technology, as well as social, stealth, and combat skills. The graphics are very crude by today’s standards, but the gameplay is outstanding.