I love fanfiction. Of course much of it is trash, badly written etc, but you can find some amazing gems in there.
I tend to go for fanfic that is about characters I feel had a strong connection in the book/show. Sometimes that’s male “best friends” who had stronger connections to each other than they did their token female “love interests”. Examples include Dean/Castiel and Frodo/Sam. Others are heterosexual couples that I think had beautiful relationships. For example Buffy/Spike, Roslin/Adama and Anne/Gilbert.
And the way sex can be written in fanfic (not always, but the best fanfic) is so healthy and beautiful! It really helped me unlearn shame about sex, because it showed how loving and transcendent explicit sex could be. All hail fanfiction, may it ever flourish.