How about someone do a story where James was just knocked unconscious by Voldemort but Lilly still died and what Harry's childhood would be like if that was the case.

 

This has been done, I'm sure, but the only stories which come to mind are wildly AU: Skitterleap and Harry Potter and the Ashes of Nurmengard both feature a widower James.

 

So does An Unfound Door by our very own Joe.

Honestly I want to see more fics of James and/or Lily before they get together, in which things are not certain just because we know how things will go from canon.