If 90's counts as "really old", I'd start with Lucas' point and click adventures from Loom to Grim Fandango.
Then there's my favorite series Wing Commander(/Privateer spin-off) or optionally for people with interest on Star Wars (and/or worse taste on games than myself...) the X-Wing/TIE Fighter series.
80's gets a little harder, first game I can think of would be Sid Meier's Pirates! (You really might want to go with the original instead of the fancy new versions. Well, except the absolutely original was in fact for Commodore 64.)
Strategy games never get old: Master of Orion 1&2, Populous 1 (I really prefer the simplicity to 2) and the original Civilization. *sigh* Oh, the days when "Sid Meier" still meant good games.