Nice idea for a topic
I think most people would tend to see their lost loved ones, especially so soon after the war. Coming out victorious over Voldemort meant a lot of personal sacrifices and I'm sure they would be constantly reminded of just how much victory cost.
I think George might see a future version of himself and Fred, "what might have been" if you will. Perhaps them standing in the joke shop, or Fred being his best man at his wedding.
I think Arthur might see himself in a better position to provide for his family. Not necersarily a different job (as he does love what he does) but perhaps a pay-rise from the ministry
As for Neville, I actually think he might see himself surrounded by the DA. I know he goes on to become a Professor but I imagine that the first year after the war might actually be a bit of a lonely time for Neville.