The Great North American Road Trip - Part I

This is an attempt to conjure up the greatest possible road trip within North America for the same cost as a round-trip plane ticket to Europe for two, around $2,000. The journey must be suitable and enticing for any sort of vehicle, be that a van, grand tourer, miata, or uncomfortable fiery time-bomb of a 70s supercar.

We will be assuming 30 mpg fuel consumption and an average gas price of $4/gal. All costs must be figured in, including lodging, food, gas, speeding tickets, and all other foreseen costs.

Part I - The Route

We will start by deciding on the general route because, for us, the roads and scenery therein are of utmost importance.

Please paste a Google Maps (or alternative) route within the comments, and explain why the route you've chosen is worthy of the title above. The max distance allowed is 15,000 miles (calculated: $2,000 / $4/gal * 30 mpg), but keep in mind we will need money for food, lodging, and extra-curricular activities, so you might want to cap the distance at some point; I would recommend at 8,400 miles (calculated: 75mph * 8 hours * 14 days).

The winner for each part will be the answer with the most recommendations.