What if Leslie and Diana were more than just friends. A short piece that popped into my head after watching the Classic Wonder Woman Episode from the third season called "The Skateboard Whiz".
Small vignettes that take place around, or most likely after each Intelligence Episode aired (or so). Using my headcanon (which was spurred by a 'Detective Bering-Wells' couple of short fics by various people on Tumblr) where Riley Neal is actually Myka and Helena's daughter.
Sequel to Quid Si. While Regina and Emma take a journey looking for Emma's birth son, there's lots going on back in Storybrooke as well, including a newcomer and some new loves.
A Year in the Life of Kim Legaspi, Kerry Weaver, and their families and friends. Each chapter (or few chapters) is a separate short story, and all are combined in this bigger way to keep them in some sort of order.
A What if Story. It takes place soon after the 03x20 Episode "Kansas" and goes from there, ignoring what the 2 Hour Season Finale brought us.