There are two Final Fantasy II's depending on how you look at it. The proper FFII was released in Japan only, but a few people translated it, and released it in the states on the NES. The American FFII was actually FFIV, on the SNES.
FFII was also redone on the Playstation in Final Fatasy Origins, and now just last week rereleased with FFI on the Game Boy Advance with new dungeons, features, etc.
It's called Final Fantasy Dawn of Souls.