Difficult to choose one so don't get me started...
Rome & Paris of course, never get tired of them.
New Zealand
Yosemite, San Francisco
Grand Canyon
West coast of Ireland
Outer Hebrides
Orkney
Isles of Scilly
Pompeii & Herculaneum
New England is something special (Shroppie, give us a ring!)
Cape Cod
Maldives
Mauritius
Bermuda
Then there are the cruises...
Just come back from a cruise round Cape Horn so Santiago, Cape Horn, Falklands, Buenos Aires, Montevideo, Iguassu Falls, Rio, Península Valdés in Patagonia
Back from Dubai so Suez Canal, Egypt - Cairo, Luxor, Vally of the Kings, Sea of Galilee
Panama Canal & drive out to Key West on the Overseas Highway
Most of the Caribbean islands
Spitsbergen
Iceland
Waikiki Beach
Cape Town, Namibia and Cape Verde
Balaclava, Sebastopol and Odessa
Plenty more left to see and many that we would like to go back to. At our age getting travel insurance is the main consideration.