Quartet (Sega Master System)

For some strange reason I found the arcade version of this game intriguing.  I'm not sure why, but I always found myself watching people play it and being fascinated.  Looking back on it, Quartet is a very simple run and gun game with not a lot to it, and yet I would always make time for it at the arcades.  It could have been the four player coop that caught my attention, since the only other game that I had seen doing that was Gauntlet.  When I play the game nowadays, it's mostly for the sake of nostalgia.  It certainly doesn't hold my attention like it once did, but I'll continue to have fond memories of those times in the arcade, and later the Master System, with it.

Fantasy Zone (Sega Master System)

It was reasonably popular when it came out, but not so many people remember Fantasy Zone, especially the young'uns it seems.  It was an interesting shoot 'em up in its freedom of movement, and being able to buy upgrades.  Really tough game too, with lots of enemies trying to plow into your ship combined with the fact that one hit would kill you.  There were some pretty intense boss fights to be had here as well.