THe Pasadena area has lots of good stuff.

The Huntington Library is actually in San Marino, just over the border from Pasadena. The gardens alone are worth a visit, but the library and museum are interesting too.

http://www.huntington.org/

If you are into architecture (or Arts and Crafts style generally), the Gamble House in Pasadena is spectacular.

http://www-gamblehouse.usc.edu/

Old Pasadena and Paseo Colorado have a number of interesting restaurants.

Also in Pasadena is the renowned Norton Simon Museum.

http://www.nortonsimon.org/aboutnsm/