Any William Gibson novel! Nah just joking, they are allready written more or less from a bystanders perspective. I would like to see Malazan Book of the Fallen by Steven Eriksen from a bystanders perspective. Now I know some chapters let you see that world from a "bystanders" perspective but that bystander almost always has some connection to one of the main characters so I don't really consider them as random bystanders.
As long as it's not someone on the Chain of Dogs! I always thought the tale of the Pannion Seer would be great as told by a refugee. The caravanserai and Iron Wolves were so interesting because they were close to the action but not politically driving it. The Mask Council was barely acknowledged, even though their decisions set the stage for the siege of Capustan. Such an excellent series.