One of the sites I've discovered recently is called Breakthrough Bookstore: http://www.breakthroughbookstore.com/
"Breakthrough Bookstore is trying to provide a venue for self-published authors to shine through the Self-Published Authors Marketplace because we want the reading public to change their perspective of self-published works and help make self-publishing a valuable and lucrative part of the publishing industry."
Check them out if you're interested in finding new hidden gems. :)
"The other parts of our bookstore are an effort to bring into one place nonfiction books (traditionally published) that can help you in different areas of your Life and Business. We want this to be a place where people can come and browse comfortably without the hassle that often accompanies trying to search with keywords on Amazon."You can also follow them on facebook where they keep their followers up to date on their activities.
"The entrepreneurial spirit so prevalent today has produced many quality books through various self-publishing avenues. You will be amazed at the diamonds you can find! Shop here and tell your friends about this special venue for self-published authors."