If you're looking for a high-end home, Franklin County has a lot to offer, real estate agents say. If you want something older, check out Upper Arlington or Bexley. Something new and huge? New Albany is your destination. Of course, downtown has some pretty spectacular condos if you want to be close to the action. For this week's cover story, we took a deep dive into the million-dollar home market, including a trip through the Franklin County Auditor's archives to see when the county's first million-dollar…