I loved Kisses Sweeter Than Wine and By All Means, Rome, too. Another spn_j2_bigbang that I really liked was tryfanstone's Kant's Dove (Sam/Dean AU): Sam's an angel and Dean's a human in a gritty, dystopic world where angels rule with an iron fist and humans are chattel. It's got an intricate and skillfully crafted plot, marvelous world building, cool outer-boroughs-New York settings, hot sex, and intense, grown-up emotion. It feels as full as a novel, though it's only novella length. Needs some line-editing and stuff, but that's par for the course.

On stargate_summer, I'm also looking forward to reading theemdash's and melanyeseahawk's stories that green_grrl mentioned above.

I'll be curious to hear if you come across any other bigbangs that you'd recommend. (I can't read any s5-spoilery ones, though, because I haven't seen that season yet.)