I have a number of arcade titles that I'm rather nostalgic for - can't really choose.
If I have to, though, a perennial favourite:
While I played a lot of the older titles back in the day (Gyruss, Galaga, Frogger, Pac-Man, Space Invaders, even Pong), the golden age of arcade titles, was in the mid to late 80s, imo (although it may have more to do with me having more disposable income).
In addition to Gauntlet (good call, Sath):
1942, Commando, Time Pilot
Wonder Boy - Monster Land (don't ask, something about that game demanded my money)
edit: What really, really rocked, though, was the Battletech pods... as seen at Intencity arcades back in the early 90s (sorry, can't find anything better than the flyer below on the interwebs):