You deff have to go to Santa Monica so. We stayed there last year in a best western hotel, but the hotel was 20 blocks from the Beach.
There is a travelodge and best western (different one) right on the beach. It is right beside the pedestrianised area. 3rd street is a cool street with loads of shops, lovely small italian restaurant at one end, bars and loads of street entertainers.
If you rent a car you can drive down the coast a bit and there are even nice beaches.