Super Mario Day!

Remix the Super Mario sounds like my favorite: duh duh duh duh duh da

Make your own question mark blocks and hang them around town

Super Mario Devo (plus 63 more, including another Katamario brother)

Mario Misconceptions

LET'S MAKE DOT CHARACTERS AND MORE YOURSELF!

Download a bunch of Video Game Remixes

Edit: More Mario Katamari (via)