+1 Marina Del Rey. Lots of areas for walking and plenty of restaurants. Not much in the LAX area, but for the areas I have walked in it was not unsafe.

Will you have a car or be relying on taxi to the hotel? There is a Renaissance in Hollywood at Hollywood and Highland (all the stars are there). Not sure how far you will walk from the hotel compared to Marina Del Rey. Same with the Marriott Downtown LA. Just not much in those areas compared to Marina Del Rey. If you are up for long walks, you from MDR, you can make it to the Promenade in Santa Monica, just up the hill from the Pier. Or just stop at the pier.