If you like your Kingdom Hearts, but hate its fandom, you can't possibly go without reading Those Lacking Spines.
http://www.fanfiction.net/s/2903858/1/Those_Lacking_Spines
Fun Fact: It was originally written as an intentionally bad trollfic, but the dude had so much fun writing it, he decided to take it "serously". It shows, it's really good!
Also, if you like bot KH and The World Ends With You, then you MUST check this one crossover out: Playing For Keeps!
http://www.fanfiction.net/s/4683313/1/
Also, if you like Cave Story, then you might appreciate this novelization of the game.
http://www.fanfiction.net/s/5733045/1/Cave_Story_A_Novelizationhttp://www.fanfiction.net/s/5733045/1/Cave_Story_A_Novelization
Okay, that's enough outta me. Happy reading!