I've been meaning to get back on Ys IV: Dawn of Ys (1993). It's one of the few Ys games I haven't completed.
Other than that, my (almost) four-year-old son has—with very little prompting form me—gotten hooked on classic Megaman games. He likes the first one, but he naturally gravitated to 2, and that is a 1988 game I believe.
Games are like books or movies to me. I do buy new stuff on release, but the majority of what I play is older because there is a lot more older stuff. Kids like it too, unless they are brainwashed into believing only new is good. Aside from Megaman, my son really likes playing Pac-Man and the original Donkey Kong.