Man, there were so many classics and little known gems... man I'm old....
Tempest (I was no good, but it was awesome even to watch a good player on that game)
Spy Hunter (mentioned below) was amazing (and Peter Gunn doesn't get old)
Karate Master (two player) - I could beat down other humans, but the damn flower pots and the bull were not my friends
Gauntlet - 4 players worth of sci-fi maze mahem (meta-game: If you got to the door and didn't have the key, block it and hope the boss killed the keybearer so you could grab it and go through for 1st slot)
Xenophobe - 3 players of sci-fi mayhem with hatching xenomorphs
Battlezone - Best early tank game
Space War - Two player, one ship looked like line art enterprise, the other a line art star destroyer, all sorts of space terrain and gravity effects could be thrown in
Galaga - more fun than space invaders, but 3 ships was too big (get two, be happy)
Joust
Head to Head Tennis - a great sit-down head to head game
Later on, John Elway's Football and MLB Baseball
The most glaring, super awesome omission: ROBOTRON!
Tron, both the first one with light cycles/tanks/spiders and the later deadly disk game, were amazing
From the list, Star Wars and Pinball get the nod
A hate on for: Dragon's lair and the hologram games with 'pick a path' modes that just sucked money with no real player skill if you knew the pattern