I live in Las Vegas and have been to the cities you mentioned. Here is my suggestion.
After arrival into Las Vegas, take in a show - "O" Show @ the Bellagio, "Ka" show @ the MGM, "La Reve" @ Wynn are the Grand productions, if you want to see an extravaganza show girl (topless or not) show, the Jubilee show at Bally's is worthwhile. Next day, go to the South Rim Grand Canyon - far but the #1 attraction in the world - it includes photo stop at Hoover Dam. This trip will take over 15 hours of your time but definately worth it if you are into taking the grandier of Nature. A bus ride to Los Angeles could take you approximately 5 hours and this also depends on where you are staying in LA. If you have been to Disney World and Universal Studios in Orlando, what do you want to do in Los Angeles? In San Francisco, take in a city tour - Fisherman's Wharf, Alcatraz...
There are number of National Parks that surrounds this area, such as Zion National Park, Bryce Canyon, Monument Valley, etc... It all depends on what you are interested in. If you have any questions, you can email me anytime.