Novalogic released a series of Comanche helicopter combat games in the 1990s. They began with the excellent Comanche: Maximum Overkill in 1992, and continued on with them until 2001.

They all used the excellent voxel shading system for generating the 3D landscapes. It worked a treat, and looked different to what other companies were doing, so had my vote of approval.

These grabs are a mixture of my own, and some that the company sent to me back in the day.

More: Comanche series on Wikipedia