Odd thing I have with Persona 3 is that I go to around the second to last day, and I just can't force myself to finish the game because the ending is just so sad... (Unfortunately I've been spoiled)
Persona 4 on the other hand, I liked everything about it and the story isn't as edgy and grimdark as the predecessor. Though Persona 3 is still a good game, it's just not as my thing.