Fly into and out of LAX (Los Angeles). Head a bit south to San Diego and the coastal towns like San Clemente, then back to LA, then Vegas, then Grand Canyon, Bryce Canyon, North then through Salt Lake City into Wyoming, Grand Tetons, Jackson Hole, Yellowstone, through the Bitterroot Mountains in Montana/Idaho to Seattle, then down to Portland, then down to Napa/San Francisco, and back down the coast to LA.

Killer loop with incredible natural scenery, as well as some big cities. Driving from New York, or even Chicago, to the west coast would not be the best use of time in my mind.