Los Angeles (aka. City of Angels) is the 2nd largest city in the USA and has a lot to offer, including great shopping (a la Pretty Woman), Hollywood, Venice Beach and sports (L.A. Lakers).
Las Vegas is the show and gambling capital of the USA. World famous and featured in many, many movies. A wide variety of hotels from budget places to top-class resorts.
The Grand Canyon is really grand. When standing on the ridge of the canyon and looking 1 mile (1600m) down to the river Colorado that created all this, you do owe the river a lot of respect. It is possible to walk all the way down and back up in a day, what can be recommended.
Yosemite National Park is one of the most famous parks in the US. El Capitan has nothing to do with water...
San Francisco is a favourite city for so many: Americans, Tourists and Homeless. The climate is just perfect for almost anything including growing wine (Napa valley) or computer (Silicon Valley). Tourist will enjoy the local cable train, Alcatraz prison and The Golden Gate bridge.
Zion National Park is one of the great national parks in Western USA featuring geology, basins, rivers and walking ways.
Monument Valley is a desert with few small, steep mountains/rock formations in the shape of monuments. The area is a "classic" and must-do in the Western USA. Of course it is featured in many movies...
New York City has a few nick names, for example "The Big Apple", "The City That Never Sleeps" and "The Financial Capital of the World". We cannot list everything that there is to do in NYC, because it is too much. The basics however are the Statue of Liberty, Times Square, Broadway, Little Italy / China Town and the Empire State Building.