What is the best persona to get in 3 portable?

The best Persona in Persona 3 Portable is Thanatos. Thanatos is a powerful Death Arcana Persona that can be fused at Level 83. It has the highest Strength stat in the game, as well as high Endurance, Agility, and Luck. Thanatos also has access to powerful skills such as Megidolaon, a powerful Almighty-type spell, and Death's Door, which can instantly kill an enemy. Additionally, Thanatos can learn the Enduring Soul skill, which allows it to survive fatal attacks with 1 HP. This makes Thanatos an incredibly powerful and versatile Persona that is well-suited for any battle.