Hyperdimension Neptunia Rebirth 1, is the best Neptunia game (and it really GOOD from what i have read it has great scores on Amazon and even the critics who dont particularly like japanese games gave it some good ratings)

the game is about the Console Wars (you know that thing this page is basically dedicated to ), there are characters that represent consoles and companys, and the game is filled with parodys about the console war (like the 360 overheating problem and the PS3 being future proof), and parodys of games from all consoles as well, (like Sonic and Zelda).

main characters: Noire (Playstation 3), Neptune (Sega Neptune), Blanc, (Wii), Vert (Xbox 360).

disgaea 4 is cool.
but the best rpg ever is persona 4 and maybe persona 3 or dragon quest 8 (ps2) : D