I have to go with IV/IVA or either of the Devil Summoner games for the sheer number of demons in those games. I think they have the most out of any SMT/Persona game iirc. I could be wrong though. SMT 3 and V, the Raidou games, Persona 3-5, NINE, and Imagine’s demon/persona smaller demon selection might be due to the fact that they use 3D models. Most of which seem to be reused and retextured. Although, Dx2 has a wide selection too and uses 3D models and the Devil Survivor games use sprites despite having a small demon pool, so idk… I love all the games though.