Shadows of Lunar for Saturn/PSone. Thing is, I went back and played Lunar about 3 months ago on my PSone and.... yeah.. it feels old. Still good, looks pretty, music is great, etc. But it shows its age.
There was only one Lunar game for the DS, and it was in '05 and pounded in reviews for being very long but filled with fluff (like making you lose health by running, so you had to walk through endless boring areas). Lunar Knights was different, and was a blast.