If you had never traveled and could only take one final vacation...where would it be in the USA

Yellowstone or Grand Canyon or southern Utah or a loop of all the National Parks in the southwest or even the whole country.

Grand Canyon - Seqouia/Kings Canyon - Yosemite - get on a cruise in San Francisco to go to Alaska

Hawaii

New York City, maxing out my American Express Card!

Hawaii -- splurge on Hana Maui hotel
Yosemite

I'm already there.

Alaska for me, but it depends on what you're interested in.

If you like big cities... New York, Seattle, LA.
A beach... Hawaii, southern California, Florida.
Parks... Washington, Yosemite, Grand Canyon, or any of the National Parks.
People Watching... San Francisco, New Orleans
Government/History... East Coast - DC, Boston
Wilderness... Alaska, Montana

It sounds like you're asking about a "kick the bucket" trip. If that's it, figure out what you want and go for it, not what other people want.

I'd repeat the 6 week trip we did last year with a few more addtions. Yellowstone for almost 2 weeks, (I'd add the Beartooth Hwy) Grand Tetons, Arches, Canyonlands Island in the Sky District, Dead Horse State Park, Canyonlands Needles District, Newspaper Rock State Park, Scenic Hwy 128, the Shafer Trail & Long Canyon 4 wheel drive trail, (I'd add Monument Valley) Capitol Reef National Park, scenic Hwy 12, the Burr Trail,(add Bryce Canyon, Lake Powell & Grand Canyon) and Zion.

So many places, so little time!
I would really like to go to a Chamber Music Camp near any of the east coast cities.

Hawaii

Iowa Redhead: Not me but my brother-in-law (at 58)who thought he had all the time in the world.

I'm sorry to hear that. I was hoping this question was just hypothetical.

If I had to plan ONE final trip, it would be down (or up) the west coast, starting in San Diego and ending in Vancouver or Victoria (or vice versa).

Beach: Hawaii

City: New York City

NYC full stop with hotels, restaurants, Broadway, The Met.