Lots of very scenic places quite close, less than 1 hour drive!
Marin County:
Belvedere and Tiburon and Sausalito and Marin Headlands, all looking back toward SF
Stinson Beach, Muir Woods, Mount Tamalpais, Muir Beach
Point Reyes, Bolinas, Tomales Bay
Bodega Bay (1.5 hr north of SF)

Angel Island, Alcatraz, Treasure Island (all are interesting and have views of SF)

Of course, there are the wine growing areas in Sonoma and Napa countries

And just south of SF:
Fort Funston area with hang gliding off ocean cliffs in the SW corner of SF
Kite boarding and wind surfing to the immediate north of Coyote Point (30 miles south of SF)
Hwy 1 coastside, including Pacifica surfing (15 min outside SF), Half Moon Bay (30 min), Santa Cruz (1 hr)