Most Tales I played weren't very meaty. Only ToS, ToV, and TotA felt like they had decent amount of stuff to do. Mainly for ToV it was crafting. ToL is crap for side quests so is ToS2 an those are the only other Tales I have played.
He who fights and runs away, lives to not have the f****** moon fall on him as an alternative - Tacitus
ToG is pretty good. There a plenty of side bosses and a side dungeon to do. There are a couple of sidequest throughout the game, and unlock most of the other Tales of games, most of them aren't hidden in the most inconspicuous places.