California State Railroad Museum (Sacramento): Old Sacramento's biggest attraction, the 100,000-square-foot museum was once the terminus of the Transcontinental and Sacramento Valley railways. It displays nearly two dozen locomotives and railroad cars, among other attractions.
J. Paul Getty Museum at the Getty Center (Los Angeles): Designed by Richard Meier and completed in 1997 to the tune of $1 billion, the Getty Center is a striking, starkly futuristic architectural landmark, with panoramic views of the city and ocean. The building itself is enough reason to visit, but so is the permanent collection, the crown jewel of which is Van Gogh's "Irises," which the museum paid $53.9 million to acquire.
Petersen Automotive Museum (Los Angeles): This museum is a natural for Los Angeles, a city whose personality and history is so entwined with the popularity of the automobile. Impeccably restored vintage autos are displayed in life-size dioramas accurate to the last period detail (including an authentic 1930s-era service station). Upstairs galleries house movie star and motion-picture vehicles, car-related artwork, and exhibits.
The Museums of Balboa Park (San Diego): Balboa's museums afford a variety of cultural experiences in a relaxed, verdant setting. My favorites include the Aerospace Museum, the Museum of Photographic Arts, the Model Railroad Museum, the Botanical Building, the Timken Museum of Art, and the Mingei International Museum of Folk Art. Check in at the House of Hospitality for a map and "Passport to Balboa Park," a low-cost combination pass to the museums.