Terranea is beautiful, up on the cliffs, it feels almost like you are in Hawaii. If you like something more urban, the JW Marriott at LA Live is also cool. Great people watching, there are about 23 restaurants within walking distance, the Nokia Theater (anything good playing the night you are going?), the Conga Room, Lucky Strike, Regal Theaters all right in the area.
Good luck choosing. My kids are a bit older now, but I remember just being happy being away and able to sleep, really didn't matter where I was!