1. Tales of Symphonia
Still the most epic of the series, where they really put everything together, and my favorite cast of characters.
2. Tales of Vesperia
Probably the grittiest of the series, and it had the best voice cast. The graphics still look pretty good on current consoles with the Definitive Edition.
3. Tales of Xillia
Enjoyed the game world, and I like Milla as a heroine.