Road Trip from Kentucky to DC 6 days, 5 nights.
 

Will be driving I-64 to Charleston and here is where we need to make the decision on what to do? Do we stay on 64 to I-81 and hit Skyline Drive or Do we take I-79 to I-68 and over. We were thinking either way we would like to stop in Gettysburg for a little while. What other stops if any? Do we to head straight to DC and spend the time there?

Whatever route you decide on, I do recommend Gettysburg and if time permits, Harper's Ferry about an hour and a half away. A place where we had dinner in Gettysburg and we loved was: http://www.farnsworthhouseinn.com/ They also have a B&B but we only had dinner there.

Take Gettysburg and Harper's Ferry for sure. If you have some time thow in the Penn Amish area around Lancaster.

We took this same trip 4 years ago - drove from Indiana and went straight to Gettysburgh. At the visitors center, we were able to hire our own guide who drove us in his own SUV to the battlefield - it was as personalized as you can make it, the guide was excellent and was able to answer all our questions, and more.

Then we went to Washington - you didn't mention if this is going to be your first visit, but I suggest a minimum of 3 days if you can. There's just so much to do. We were able to get a tour of the Capitol (do this way ahead of time). The one new thing we did during our last visit was tour the monuments at dark - so beautiful!

Then we went on to Jamestown for the last 2 days of our trip.

If you have the time, why not stop at Gettysburg on the way to DC and take Skyline Drive on your return? Front Royal where the Drive begins is just over an hour from DC via I-66. You would then have several options to exit the drive between Front Royal and Waynesborro to get over to I-81 if time were a factor.