Gauntlet is a good idea but it doesnt make my list. These are genuine, vintage arcade cabinets, ye?
I would go for:
1. Pengo
2. Vanguard
3. Time Pilot
The first two because, although they are shit in gameplay, the music is the most amazing chiptune ever - when delivered through that cabinet, with those speakers.
And Time Pilot because i like to play it. I genuinely rubbed my skin off on that game.
Notable mention for Sinistar again for the sounds; Beware, I live!! I hunger!!
Crossbow was pretty darn sick too ..and so was Heavy Barrel.