I was poking around eBay today when I noticed an auction for a Metal Gear novel based on the NES game, and it got my memory jogging. It was published by Scholastic (i.e. school fairs, book clubs, etc.) and I wasn't able to see the author's name. Of course, these were novels in a loose sense of the word, they're only about 80-100 pages long, and contain hints on how to beat the game.
I seem to remember reading a Super Mario Bros. and a Mega Man one before, but I haven't seen any in a long time. I thought it was pretty cool.