Agree about LA not being much of a vacation spot - although the other 'big' CA attractions are simply stunning.
Yosemite is spectacular, some of the most amazing scenery I have ever seen.
The variation between the lushness of Yosemite and the death valley desert is really surprising. Like being in a different country.
I wish I'd seen more of the PCH. For two days of the drive we did it was soaked in fog. Couldn't see a thing. Santa Barbara is very nice though.
As for Vegas - make sure you stay in a 'name' strip hotel for the full on experience. Paris and Bally's have good location and vfm imo.
www.hoteldiscount.com for cheap rates.