Sort of surprised no one has mentioned these hotels, Chateau Marmont
http://www.chateaumarmont.com/
The Avalon, not for everyone but definitely has its charms
http://www.avalonbeverlyhills.com/

The ultra luxe Peninsula Beverly Hills
http://beverlyhills.peninsula.com/
And Raffles Beverly Hills
http://beverlyhills.raffles.com/

As for Santa Monica there is
The Huntley Hotel
http://www.thehuntleyhotel.com/about.php
The Lowes
http://www.loewshotels.com/en/Hotels.../Overview.aspx

Hope this helps
SAM