That's a tough choice! Obviously, playing the original on the PS1 would be fun for nostalgia's sake, but then the PS4 version had many enhancements that improved the game.

I recently played the version that came with the Requiem Collection found on the PS4 and it was a great port. Not only was it upscaled so you could play it in HD but it also used the new translation (and voice cast) found on the PSP version. Konami also included some of the bug fixes and features that were added to the Saturn version.

Honestly, I think the PS4 port may be the definitive version of Symphony of the Night. :D