I can't believe I've never posted a rec to this before. But.
Dumbledore's Army and the Year of Darkness by
thanfiction This fic is pretty much the most amazing piece of fanfiction I've ever encountered. It's about what happens at Hogwarts during book 7. And gives a lot of character development to all the minor characters.
And Neville is super awesome.
But really, it's one of the few Harry Potter fanfics I'm willing to read these days.
(The other recent one being
"And On the Third Day" by ~recessional over at Dreamwidth. H/R/H OT3, set right after HP7)