So I just got Super Mario Maker. Rather than flood my page with all my levels, I'll just keep this post updated for anyone interested. Enjoy.
First off, my profile on Super Mario Maker Bookmark. See below for individual links to the courses and screenshots.
EDIT from 2021: The Super Mario Bookmark site has been discontinued, so I have changed the above link to the archive.org equivalent. I have removed the now-useless individual course links that were in the below listings, though I believe you can still use the download codes for the time being.