Well, I prefer longer fic, so my MO when gorging on a new pairing is to look them up on AO3 and put the results in descending order by word count. This meets my needs, but it doesn't necessarily lead me to any hidden gems you wouldn't already know about. With that disclaimer ...

Your Bottle Is Empty: http://archiveofourown.org/works/73779

Starting from zero got nothing to lose (HS AU):
http://archiveofourown.org/works/224111/chapters/338950

The Trickster Saga: http://archiveofourown.org/series/4291

Highway of Love: http://archiveofourown.org/works/171194

and the hilarious Cash out, Get the Hell out of Town:
http://archiveofourown.org/works/154607