This is a tough question... so many possibilities.
First thing that comes to mind is the Cadillac Hotel in Venice Beach, CA. Fun, sunny, laid-back area, easy to get to, lots to do. Close to the Getty. Not too expensive. Biking/rollerblading at sunset is wonderful.
http://www.thecadillachotel.com/
The Santa Monica library is also a great resource and alternate place to work if you are tired of coffee shops and hotel wifi.