It depends on what you're looking for.
Bard's Tale Trilogy is first person grid based dungeon crawling, but with non-tactical combat (like Might and Magic combat-wise, but better in that respect). Dragon Wars is also recommended, though with less of an emphasis on combat/dungeon crawling, and more of an emphasis on non-linear exploration.
SSI made some other games. The Dark Sun games are the closest successors to the Gold Box games, albeit with the entire game being in overhead view. Eye of the Beholder is real-time grid-based dungeon crawling, though I think some of the other games in that genre (like Lands of Lore and Anvil of Dawn, for example) may have better mechanics.
A few Wizardry games are available here. Wizardry 6 and 7 are first-person grid-based games with non-tactical turn-based battles. Wizardry 8 gets rid of the grid, and your party and the enemies can move during battle (though your entire party moves as a unit, so I wouldn't call it tactical). Wizardry: Labyrinth of Lost Souls is like earlier Wizardry games, with the town being just a menu, but I think Elminage Gothic may be the better game if you're looking for this style.
Of course, if you're into D&D based turn based tactical combat, you might try Temple of Elemental Evil or even Knights of the Chalice (the latter even has a demo, though the demo can be rather difficult, harder than the full game).
You might also consider looking into the various Spiderweb Software games, like the Avernum series.