Final Fantasy VI will always hold a special place. There tries not to be one “main” character and you get back stories and growth of most all of them (Gogo and Umaro notwithstanding). The fact that you can complete the game with as few as three or as many as all 16 too makes if very flexible in your choice of characters.
This is an easy one for me, Tales of Berseria. No character gets ignored by the narrative, or peaks in their introductory arc. The characters also build personal relationships with each other that don't depend on the protagonist, and aren't just one-offs or side content. I would recommend it to anyone, doubly so if they're a fan of the "dysfunctional band of misfits" setup.
Final Fantasy Tactics has Agrias Motherfucking Oaks and other jrpgs don't so I think we can close out the thread
Final Fantasy 15 has a great core party. They all have a relation to each other and a lot of the game is focused on banter between them. They feel really natural in a way. It's definitely the best aspect of the whole game. Each of the support characters has a DLC episode just about them and there is even a short anime with additional backstory for them. I don't think I'd rank them in my top 5 individually (although Ignis comes close) they are the best overall team.
I love the cast of Persona 4.
They really nailed that feeling of a group of friends out to solve a mystery. Even better if you played the Golden version of the game.
While I love 3 more as a whole story-wise I feel like 4 developed the bonds of the supporting cast much better and showed how they all cared for each other.
All the events and trips you could go on with each character really developed them out nicely and it was great helping them overcome their personal issues and grow stronger as a person (and in battle thanks to the perks and advanced personas).