1: Avatar: Establishment, Book 2 by Dark Pen This is a delightful exploration of spirituality and BDSM. Several of the scenes are incredibly hot. The characters face shame but are not shamed for their desires. It's a world in which people can rejoice in their sexuality and explore each other with compassion and love.
2: Carl Naked in School by peregrinf I ran across this story as I was facing my own sexual awakening many years ago. It brought me to the idea that love and the work of the lover are things we can choose to learn and explore openly. I thought it did a delightful job of actually capturing someone facing and stepping past their own shame as a lover.
3: The Collar Around the Heart by Old Softy An interesting exploration of how a D/S dynamic builds up in a very different world. Contains some non-consensual elements, although things build to a loving poly relationship.
4: Kelly by The Night Hawk This is a wonderful poly romance. It shows a group of people growing and challenging each other together. It shows that there can be conflict when we love multiple people, but it also shows the joy we can find when we step beyond society's limits.
5: R and R by Thinking Horndog Thinking Horndog is a master at exploring complex emotions, D/S, and exploring consent and its lack. His characters are real, and while his stories are dark, there is generally hope and growth. Reading R&R caused me to think. At one level what happens here is repulsive. However, for some of the characters it is a truly wonderful experience, and the world is painted well enough that I can entirely believe that.
6: Strange Relationships by Thinking Horndog This is a disturbing but compelling exploration of D/S with rather less consent than you might hope for. Yet even so, the characters seem very real, and it poses a lot to think about. Amazingly well-written.