If you've played one "Tales of" game, you've played them all IMO. The battle system evolves, and the art changes, but the plot is always the same generic J-RPG nonsense that it will always will be.
...which I mention as it makes it hard for me to pick a favorite. I'm playing Graces F now, but I'm not really a fan, especially now that I've progressed to where it has become a moe-blob harem for the main character. That characters are getting all holier-than-thou because
Warning: Spoiler!Richard went berserk and killed one arbitrary guard when the party has killed hundreds of guards
annoys me but crap like that crops up in every Tales Of Game.
Is it just me or does the voice acting in Tales of Graces F suck? Even though it has the son of anime legend Bryce Papenbrook as the main character, and other experienced anime/game VAs on board, it sounds stilted and cheesy to me.
I think I'll go with Symphonia as it was a fun co-op game, I'm partial to its combat/tech tree setup, and even though they were punks, it was the last game with male characters that actually
looked like male characters. Tales of Vesperia, I'm looking at you