First, Persona 3 & 4 ending off course.
First battle in Persona 3.
The last battle when the main hero get support from everyone.
The battle against our own party in Persona 3 FES (Heartful Cry is very touching
).
All character feelings resolution in Persona 4 when they first got a persona.
Burn my dread is really cool.
(I'm just playing Persona 3 & 4, so i don't know about Persona 1 & 2)