I think he is looking to complete a publisher. The Atari silver label collection is an ambitious one with Quadrun, Asterix, Crazy Climber (one of my favorites), Waterworld, Obelix, Rubik's Cube, and of course (the rarest) E.T.
Sega is a decent candidate in terms of gameplay. Tapper and Spy Hunter are awesome games and there are only 9 games. Very achieveable if you're not talking CIB.