From the Los Angeles Times (April 2010):
Applicants to UCLA and UC Berkeley once again had the hardest time. UCLA accepted only 21% of in-state applicants, compared to 21.4% last year, and UC Berkeley admitted 24.5%, down from 29.5% last year. The next toughest were UC San Diego, 36.8%; UC Santa Barbara, 41.7%; UC Davis, 44.5%; UC Irvine 45.4%; UC Santa Cruz, 64.9%; UC Riverside, 77.4%; and UC Merced, 78%.
This is for in state.
For out of state, both UCLA and UC Berkeley are very selective.