I suppose you could call this a necro-bump, but I've recently dived into writing fanfics in The Melancholy of Haruhi Suzumiya, which has a fandom that I'm relatively impressed by. Most of the fanfiction I would say has some merit and is very entertaining to read.
I'm a fan of drama, and Haruhi really works well with drama, so I would say that if you are searching for a nice story to read, you should look at these two in particular.\:
Unmasked Eyes, a story about Koizumi reflecting on his true purpose in the Brigade.
and
The Death of Haruhi Suzumiya, Self-Explanatory, but amazingly entertaining
Stories on humor or romance are more common though, so if that floats your boat, that's fine. Currently, I'm working on my own story in the genre. I'm trying something rather different and rare compared to other writers. There is an original character but I do believe that shouldn't ruin your reading experience. And this is a series I think that works well with original characters since interaction plays such a strong role in anything that happens.
The Cracks of Broken Mosaics