Mine was Donkey Kong. I also liked watching the movie on it that showed the competition for achieving the highest score, it is called The King of Kong.

Ghosts & Goblins. Saw that somebody had made it for a pi, but never chased it dow. Good luck! Sounds like a fun project!

I built a MAME arcade 20 years ago, see some photos in this post [agnostic.com] . I don't have it anymore, gave to my daughter.
Hard to choose a favorite since I played many during the golden age of arcade games. Missile Command was up near the top. A couple of us would sit and play for hours on one quarter if you hit the magic 810,000 point bug where you got the extra bonus cities. Had lots of fun.

Asteroids