My spn_j2_xmas fic (A History of Violence, written by lyryk) is perfect.
I imagine it would be really hard to write the brothers at this point in their story. They are in such a complicated, messed up place. The author does an amazing job of capturing both of them in this fic. It's bleak and sad but it holds an undeniable truth that's both hopeful and heartbreaking. It's also beautifully layered. Go read! (It's very mild Sam/Dean).