Daniel Brown, a very young pianist living at Virginia documented most of the Nintendo game music. Those piano songs include music from Mario Bros and Final Fantasy IV. This site is recommended for intermediate and advanced pianist. Daniel arranged most of the songs and most of them even comes with complete sheet score. If you love playing Nintendo games, this site might be the source for you to increase your repertoire. All the piano recording is available in mp3 form. There are also 3 videos available showing Daniel playing the songs.
I highly recommend this site if you love playing Nintendo games. Your interest in gaming will keep you practicing all those highly sought skill in order to play the score. Have fun doing it!