If you are looking for well written stories, I wholly recommend Megan Derr.
She can be found at amasour.com.
Granted her stories are not explicit, but her writing style is so entrancing, you don't miss the smut so much. Her site has tons of stuff including several long, completed novels and for now it's all free.
As for the best m/m story I have ever read, that would be Snowflakes and Embers by S. A. Payne. Unfortunately not free, she has a pay to read site, but if you regularly purchase ebooks for about $4 buck for about 100 pages, you may not mind paying $10 so that you could read this story that is several hundred pages and numerous other completed works on there. All her stories are very explicit and well worth it. sapayne.com