Great list, Cycles! Ultima IV and Ultima Underworld could reasonably make any list of the Top Ten Most Influential Games. Particularly Underworld - this is THE basis for the first-person shooter as we know it (since Underworld leads to Wolfenstein 3D, leads to Doom, we all know the rest).
For anyone who likes these sort of lists, check out
http://www.unikgamer.com/, it's pretty fun.