Well, I agree with what everyone said except aj415. Why would anyone want to visit the west coast, but skip Seattle, Portland, the redwoods, Santa Cruz/Monterey, Yosemite, Hearst Castle, Solvang and Santa Barbara so they could spend their time only in SF and LA. I mean I understand more time in SF, but I lived in the LA area for over 30 years and still wouldn't rank it over all those other places. (Must be a nightlife person only)
Also, Las Vegas, the Grand Canyon, and Lake Powell are otherworldly--although massively out of the way if you have limited time.
You either need more time or you need to figure out your priorities. Are you a nighlife person--then aj415 has got it right (along with Las Vegas).
Are you into backpacking and nature, then Mt. St. Helens, the Columbia gorge, Death Valley, Crater Lake, Channel Islands, Yosemite, Sequoia, Redwood National Park, Big Basin State Park, and the California coast between Carmel and Morro Bay should be your highlights.
Interested in tourist attractions--then Space Needle, Hearst Castle, Lake Tahoe, Las Vegas, LA (Disneyland , Knotts Berry Farm , Universal Studios, and Seven Flags Magic Mountain), San Diego (Sea World, San Diego Zoo, Wild Animal Park), and Rosarita Beach (Fox Studios Mexico) are your places.
Only you know what you are interested in.