In this post I will recommend some awesome cave story websites!!
http://www.cavestory.org/index.php - Tribute Site by Skyewelse and Andwhyisit. It has download links for Cave Story and all of Pixel's other games. You can sign up, join the forums and submit fan art. Really awesome ^_^
Add me! I'm Kanpachi! :)
P.S : If you're going to join the forums, do not, UNDER ANY CIRCUMSTANCES make a thread called Cheesetown. :P
http://cavestory.sebastianwolff.info/ - A website made by Sebastian Wolff which includes sheet music and mp3s for all 36 Cave Story tracks. Also includes duets (or pieces for 4 handed people) This is a video of Sebastian playing the tracks....
http://hp.vector.co.jp/authors/VA022293/ - Pixel's own website. It is in Japanese, but you should be able to translate it (depending on what browser you have). You can see how his latest game 'Rockfish' is being developed and you can see some of his artwork. But the awesomest feature is his BBS, where you can send messages and he always replies! ^_^
http://cavestory-dsi.com/ - Another Japanese site. All about Cave Story on the DSi and 3DS. Has some adorable artwork :)
http://nicalis.com/ - The website of NICALiS, the company that made Cave Story Wii. You can see some of the other games they have developed. You can also contact them, but I wouldn't count on getting a reply...
And that's it!
If I've missed any awesome sites, please comment and tell me ^_^
Curly Brace :)