More Details When Merging Leads

It would be great if there was a bit more information to help me figure out which lead is which when merging leads. Telling me Lead 1, Lead 2 and Lead 3 doesn't really help determine which lead is which. I would like to determine a handful of fields to show when I go to merge leads so that I can have the "Updated At" as well as, say, "Created At."

Often times I want the oldest lead to be the default lead, but I don't really have a way of figuring out which lead that is.