Dragon Quest IV preview at 1up.

"Dragon Quest IV -- better known to Americans as Dragon Warrior IV -- is often regarded as the finest RPG ever to appear on NES. Epic in scope yet modest in its focus on the tales of seemingly normal townsfolk, DQIV represented the pinnacle of Enix's 8-bit efforts. Such is its reputation that Square remade the game a while back for PlayStation, making use of the Dragon Quest VII engine, but the development team responsible for the enhanced port was dissolved before it could complete an English version of the game. And so DQIV remains one of the rarest and most expensive NES games; simply finding a copy can be tough, and finding an inexpensive copy is even tougher."

Full Source: 1up