Xevious (Namco, licensee Atari) 1982
Xevious is a topdown, vertical scrolling shooter, featuring multiple waves of air andground-based targets. The game was widely coppied and many later games arediscribed as being "a little like xevious" eg 1942, Tiger Helle. Forthe time the graphics were truely stunning.
One of my favourite games. I playedthis on a cocktail machine when I was 13. This is the game that made me think "Oneday I'll own one of these".