The position this game takes is really a matter of personal preference, and I suspect may have something to do with which game you played first and where you started in the series.
Some fans will fight to the death over their preference of Persona 4 to Persona 3 -- and vice versa. I'm more in that second camp that prefers the earlier game. Not that there's anything particularly wrong with this entry (note its high ranking in this list), but the characters, music, and style of 3 just edge this one out.
This one had a bit of a different tone than the previous games, being more of a murder mystery. It's also notable for taking the social link system from the previous game and expanding it even further.
While Persona 4 originally came out for the PS2 all the way back in '08, a remake titled Persona 4 Golden was released on the PS Vita in 2012, bringing the series back to the forefront in the long, long wait for Persona 5.