A really, really good one-parter:
With Quill in Trembling Hand by
CiirceeA Neville story set during PoA. Overall winner, First Annual Sugar Quill Fan Fiction Tournament (Category: Drama).
This is a fantastic POV piece from Neville after Sirius Black gets ahold of his list of passwords. I adore this. Simply brilliant.
In fact, just read all of Ciircee's fics. I'm making my way through them now and I'm absolutely mesmerized.
Dream a Little Dream of Me, in which Harry dreams of what his life might've been like, is beautiful and heart wrenching, too.