If I were ranking these based on story and characters alone, this would be #1. The main character, and nearly every character, has flaws that make them more human. Yuri is not perfect and is willing to get his hands dirty for the greater good.
The story is one of two best friends that go their own paths to make the world a better place. Yuri meets many people along the way and they each have their own flaws and goals. This game probably has the most interesting and relatable characters in the entire series.
The game is also gorgeous and really shows how beautiful of a world Tales of games are set in.