I own Nocturne but remember finding it difficult (haven't bothered try again in years).
My favorites are: P4 (Golden, obviously) Devil Survivor: Overclocked Devil Survivor: 2 P3 (I have yet to play FES or Portable and have not finished the game)
I also played Strange Journey on the DS. It's not bad, but if felt like an old school, first person dungeon crawler/rpg. Also, can just get annoying at times. --- GT/PSN: Silt44 My Blog (Comics, Video Games, and Movies): www.arbitrarynerd.blogspot.com