I highly recommend AKA Beverly Hills and love staying there when I need to go to L.A. for an extended period. It does Spago catering (instead of room service), which is a cool added touch. They treat me so well. Suites from $485 a night; minimum seven-night stay.
AKA Beverly Hills, 155 N. Crescent Drive, Beverly Hills; (310) 385-1924, http://www.bit.ly/1iTWxgL