EDIT: lol, forgot this is RPGs

Xenogears is unique in how big the scope of its story is and how it really takes you places you wouldn't expect.

Soul Hackers really feels like an episode of X-files or something. The story is interesting and the combination of cyberpunk and Native American folklore is really one of a kind.

Persona 1 is also very unique. In the worst way possible. The B-horror plot is ridiculous, but even that would be bearable if it weren't for the clunky mechanics like battle positioning and the way elemental affinities are presented that are so horrible that this game has aged considerably worse than Shin Megami Tensei I, which is a much older game.