I've really been enjoying my Total Nuclear Annihilation and Taxi for three reasons:
A repeatable goal that's attainable, but challenging, and requires a variety of shots
Satisfying feedback from the machine when that goal is reached
Great Music!
I haven't had an opportunity to play many pre-DMD games, but there must be quite a few that hit these three marks. Can anyone recommend similar machines that I should keep an eye out for?