Underrated because the game itself was often kind of lacking in terms of solid foundational TPG systems…

Arcanum: Of Steamworks and Magick Obscura

Pretty good attempt at putting a Middle Earth type world ahead a few hundred years in the midst of an Industrial Revolution.

Really thoughtful stuff like the labor exploitation of certain races like orcs, with quests like a half-orc you can help start a labor union or help the shop boss shut down the nascent union.