There is a wide range of quality in the indie market. I've discovered some exceptional indie writers by scanning the book awards sites. As a mystery fan (and author) I use this link to see the various awards in my area of interest:
http://awards.omnimystery.com/mystery-awards.html. The top quarter of the list is comprised of famous authors competing for well known awards. Midlist authors compete for awards in the middle half of the list. And, the indie awards are found on the bottom quarter of the page. I copy and paste book titles from the awards lists into the Kindle search screen and sample the ones that interest me.