Hello Everyone! Happy 4th of July!!

I'm planning to drive across country with 2 to 3 drivers. I'd like to take a scenic route but not spend too much time off of the road. We have about a week more or less and would like to fit as much fun in those days as we possibly can. Could anyone suggest some "Must-See" activities along the route? I understand there are a few options as far as which direction we may start the Journey. The Northern, Straight through, and the Southern Route.

Please give suggestions on:

Which route is best?
What Items we'll need to survive the trip?
What are the Best Places to Stop and See?
How much money should each person Carry (Cash)?

Thank You For Your Time Have a Happy and Safe Holiday!! :)