Just got back myself and have been a few times. We did a road trip in a convertible Mustang and did Los Angeles, Hollywood, Malibu, Venice Beach etc. then travelled Route66 to stay for 10 days in Vegas. Grand Canyon (a long drive but well worth it) and Hoover dam are a must see and Vegas has plenty to see and do.
Go to Freemont Street, try the rides on the top of the Stratosphere, go to the shows, as well as all the other attractions inside each hotel.
If you get stuck for things to do in Las Vegas then you haven't looked, there's loads to keep you entertained including the "Ladies to your door" (guaranteed you'll come across them, if you'll excuse the double entendre
!!)