the psp version would be the objectively best one to play. there's no grinding for class points to switch jobs. jobs are more balanced. all of the new content from the ds version is included and it isn't locked off behind the multiplayer feature; so you can get the ultimate gear, the new class that was added in, and the new hidden dungeon that's perfect for exp and elixir farming along with a super boss to fight at the end of the dungeon. and i think there was an auto battle function added in, which can help with some early grinding for exp and job points through out the game.