The Marin headlands offer a unforgettable (and convenient!) experience with the rugged California coast. On a clear day, San Francisco is on full display and the temperature is reliably higher on the north side of the bay. Many stunning Golden Gate Bridge photos are shot from the headlands.
Be sure to waft in the California sage, and look above for the some of the many soaring birds. There are some delightful beaches on the backside of Conzelman Road (past the peak, where it becomes one-way). There are great trails for hiking and mountain biking as well (Marin County is widely credited as the birthplace of mountain biking).
For those on foot or bike, regular ferry service runs from Sausalito to SF. For those driving, be sure to allow some extra time for bridge traffic in the afternoons.
Website: http://www.nps.gov/goga/marin-headlands.htm
Wikipedia: http://en.wikipedia.org/wiki/Marin_Headlands
