I must say that I'm simply amazed with Crisis Core, it's incredible storyline, the graphics, it all mixes into one of the best RPG's you could ever imagine. FFVII was a revolution for the RPG series, it sprang a movie, two games ("Dirge of Cerberus"and now "Crisis Core"), and even a game that players could play on their cell phones ("Before Crisis").
But what truly is the best aspect about RPG games is the storyline, my favorite games are from VII-XII (and soon XIII), but before in the original I-VI FF games, the storyline was a bit dull. Of course it's not to say that they were uninteresting, but they lacked the quality of fascinating story that the later ones have. FFVII is a game that indulges the player into a the FF world itself, be it playing the fun mini-games (like chocobo racing), or battling monsters to train your characters and their materia to be the best of the best, or just keep beating Sephiroth over and over and trying to defeat Emerald and Ruby Weapon's. FFVII is an instant classic, and I have to say that I welcome "Crisis Core" into the saga with open arms.
Never has there been a PSP game that lets the player feel he's in the story itself, "Crisis Core" uses the same Action/RPG style of "FFXII", and it just goes so well with the PSP's graphics and functions. You can learn more about "FFVII" and it's prequel "FFVII: Crisis Core" at the following places:
http://www.gamespot.com/, http://www.ign.com/, http://www.square-enix.com/, http://www.crisiscore.com/, and if you google it many more results will appear.