Major Havoc - Atari's best if not THE best vector game ever, especially for animation. It also has aged extremely well after 20 years.
I, Robot - very original, very spacey, very underrated, which is too bad since it aged so well 20 years later.
Tempest - right to the point, original idea, very hypnotic. A perfect example of the beauty of minimalism of vectors.
STUN Runner - another that has aged extremely well, especially for a sit down racer.
Battlezone - another that has aged extremely well for all of its minimalist and now almost primitive graphics.
Quantum - another extremely underrated vector game. Another example of both graphic and play simplicity that has aged well. Another cult classic.
Black Widow - one thing that you can only get from vectors is how everything looks electric. Another trance inducing game. Another very underrated game.
Xybots - It shouldn't have taken this long to come up with a 3D take on Berzerk, but it's still a winner, and was also overlooked. Robot death sounds are hilarious.
Okay, so I only have 8. They still count.