I agree we need more information. It really depends on what you want to do in LA.

If you want to see Hollywood, downtown LA (not that there's anything to see), West Hollywood, etc, then the Renaissance Hollywood would be a good choice since it is in the middle of hollywood and next to Franklin where you could drive up to see the Hollywood sign up close : ) You can walk along hollywood blvd and perhaps check out a few venues there, see the Mann Chinese theatre, etc. There's also a metro stop in Hollywood (again, the metro in LA is useless). But, you could take the metro to Long Beach, or Pasadena, but both require long and complicated transfers.

If you want to see the beach life, I'd suggest paying a visit to Venice beach and Santa Monica. Those are more hip n happening beach communities in LA with lots of artsy cafes, restaurants, and interesting things to see. In that case, you can stay at hotels in Santa Monica (a few botique hotels there), or Marina Del Ray.

I personally prefer the beaches in Orange County like Newport Beach, Laguna Beach etc. Things are more laid back in OC and the beaches are gorgeous. They are also a bit less poluted than LA. If you like things more laid back, friendly people, cleaner area, etc, you can then stay in Laguna Beach (St Regis Monarch Beach or Ritz Carlton Laguna Hills). From there, you can do some hiking at crystal cove state park, play a round of golf, go to the beach, or take a boat ride from Dana Point to Catalina Island.

If you need specific suggestions feel free to PM me