Having grown up in California and lived here most of my life I have to say the drive from SF to LA down highway 1 through Big Sur (Steinbeck Country) is a must. It will take you through Monterray down the wine country coastal regions and even Santa Barbara which is heavenly. It takes about 1.5-2 hours longer than the 5, but you get scenery like Big Sur and the Pacific Ocean, as opposed to smelly dairy farms.
Personally I'd skip the tourist spots like Fisherman's Wharf in San Francisco, and opt to appreciate a city the way the locals would. Thats how I like to travel.
