Falcon 3.0 absorbed me for the longest time, especially after "Operation Fighting Tiger" expansion came out. When I finally had a reason to buy a computer that even my wife couldn't refute (grad school, MSEE), I went out weeks before I got the computer and bought Falcon 3.0.
From my Atari 800 days (am I dating myself), the best game I had was "M.U.L.E"...spent many a late night and six-pak of MGD (hey, I was on a budget!) playing that with buddies from work.