Descent 2. Also, if I haven't played them in a while I will gladly pick up any of the old LucasArts adventures, dust them off, and jam em in for some brain-teasing goofy fun.
Oh yeah. Another LucasArts game is Afterlife, great balanced micro and macro management, stellar voice acting (You guys will recognize Richard Barnes's voice, even if you don't know him by name), a worldly and pleasing soundtrack, and a great sense of humor about itself. It is the only sim game where half of the game is intended to do the exact opposite of other city sims: make the roads long and meandering, crowd buildings next to more hideous buildings and overall make hell the most unpleasantly hideous monstrosity that SimCity fans will just cringe at.
And, with that, SimCity 2000. Classic.