Turn-based JRPG that progresses its story along a one-year calendar system. It blends traditional turn-based dungeon combat with social simulator activities that further develop the bonds between the main character, other party members, and other major NPCs.
One of the big attractions is the emphasis placed on character interaction, character development, and thematic identity; Atlus really puts in work to make sure these are all top-level. They are easily stronger than your average fare. The series also uses real-world mythology as the basis of its primary combat mechanics (you create, recruit, and summon Personas to use in battle, which take the form of monsters, heroes, demons, and gods from the various mythologies of history).
It's honestly pretty different from any non-SMT games out there, so the comparisons don't come easily.