As the owner of a growing web site, I found myself wondering; what are the top ranking free link exchange sites that have quality, relevant links? I'm compiling a list by cross referencing with all major search engines, and excluding any with unreasonable requirements. So far, I'm excluding them if they require you to backlink from your home page, or if they require you to upload/execute code:
I will continue to work on this list as I get time!
Update July 2, 2011 - Any link exchanges that are making it difficult or impossible for me to change the domain for ECP are now being removed.
Update July 17, 2011 - If your crawler doesn't have a user agent header, you are now being removed. Fix your stuff people!