Persona 4 is so damn good. I remember playing it on the ps2 and thinking how it's use of a Time Limit mechanic totally worked for the game. Other games that use a Time Limit fail state are usually frustrating as hell and yet in Persona 4, it really does add tension. I never actually failed from time running out in Persona 4, but I always felt it looming in the distance.
The game also gives insight into what it's like to live through the Japanese high school experience, which is great because it shows players another point of view like any good RPG should do.
For me, I'd love to see a game like Persona 4 that reduces the amount of dungeon crawling and purely focuses on the character interactions and the world you're in.