Niggles: Whats left of the pre 2k period which people want to buy? Many of the "big name" ones left are either in IP hell, or holders don't want to release here...
pre 2k... Not sure... I'm sure there's some i'd like to see for completeness sake, but not to actually play. Jetfighter series, Mechwarrior series,
Links (golf games), alley cat, Questron, plenty of Atari/Apple/Commedore64/8bit systems with full libraries...
But some of the games i'd more likely want to see are a bit newer than that. Like Baulder's Gate Dark Alliance 1+2, Panzer Dragoon Orta, Destroy all Humans, Reign of fire, Marvel vs Capcom... etc....