10) Shining Tears - Even though I didn't care for each character's personality all that much, what I really liked about this game was that almost all the characters had strong ties to the plot. Each character had a good reason to be in the game and there were scenarios throughout the entire game where certain characters would become the focus, making them relevant throughout the plot.
9) Trails in the Sky 3rd - I liked that the focus on the entire game was on Kevin and Ries with the other characters playing support to them. I found their story much more interesting than Estelle's and Joshua's, and it was nice to see how the new/rarely playable characters interacted and played off the others.
8) Final Fantasy VIII - This party wasn't the best developed ever, but I still enjoyed each character's distinct personality and their interactions. The party also felt a bit more grounded/realistic than other parties so I enjoyed that element of their characters.
7) Arc the Lad Twilight of the Spirits - There are 2 different parties in this game, and both play off of each other well. I love the duality between each cast and how they turn from being bitter rivals, to becoming more understanding of each other.
6) Xenosaga - You spent 3 games with these guys. It was hard not to get attached to them, at least for me. They were a well-developed, grounded cast and even though chaos and Ziggy didn't have a lot of screen time, none of them felt superfluous either.
5) NieR - Fantastic set of characters. This party was small, but they all felt important to the plot and they felt pretty offbeat compared to typical JRPG parties.
4) Persona 1 - I like that these guys weren't super buddy-buddy with each other like the other installments and still teased/criticized each other quite regularly. I also like that most of the characters don't have their entire backstories and lives explicitly mentioned to the player and that you have to talk to them and other NPCs regularly in safe areas to understand their thought processes and lives.
3) Baten Kaitos Origins - A very well-done party, IMO. Each character has a strong personality and plays off of each other well. They all have scenarios in the story where they're the most prominent character and they all have strong ties to the main plot.
2) Suikoden III - You have 3 main characters with an extra 4th, and each have their own specific party members with their own unique interactions and quirks. If I had to choose one, however, it'd easily have to be Geddoe's party. Ace and Joker's dynamic are one of my most favorites in all of the JRPGs I've played, Jacques' infatuation with Aila is downright adorable, and Queen's sarcasm and biting remarks work surprisingly well with all the party members. The weak link has to be Geddoe, but the rest of his team more than makes up for his drynes
1 - Koudelka - Easily my most favorite JPRG party. The party members in Koudleka are fairly mature and grounded and have a sense of realism most JRPG characters don't. They're all well written and each character has a good reason to be in Nemeaton. You also see many sides to each character, and their interactions pretty much make the game, IMO.