Persona 4 is not your father's RPG. In fact, it's not really the kind of RPG that you are most likely used to; even if you are a MegaTen fanboi like me. P4 starts with your silent protagonist moving to a quiet, foggy village and attending high school just as a murder spree begins. The high school and Social Links system will make sense to those who have played Persona 3.
To those who have not played P3, your social links and the people that you hang around with and stuff you do during the day in high school will affect your Persona (think summoned critters) abilities when exploring the Midnight Channel.
Which brings me to the Midnight Channel. The MC is basically the device to make role-playing action happen in the Persona universe (which is a splinter of the Shin Megami Tensei If universe which was a splinter of the Shin Megami Tensei II universe...confused yet?). You navigate through the various randomly generated dungeons and attempt to save people who have been dragged into the Midnight Channel. If you do not save them, then they will end up dead in the real world.
The artwork and presentation are stylistic and stellar, which should be no surprise to players of the previous games in the series. If you enjoy collection games and RPG's with a ton of content, great storylines, and wonderful characters that aren't afraid to push sensitive envelopes, I strongly recommend Persona 4.