I've always liked going to the restaurant in the Theme Building at LAX, which has been through several operators over the years. It looks a bit isolated from the terminals (it is right in the middle, landside, between them all, and quite easy to walk across to), but the structure itself with it's Buck Rogers-style architecture still has to be the icon of the airport. You really need a couple of hours to spare rather than be in a rush. Also if you're staying at one of the many airport hotels the shuttle van will be able to take you there, of course.
There are great views out across the airport; have a good look round all the tables before they seat you to ensure you are getting the best view. Contrary to much LA opinion, the restaurant doesn't revolve.
http://www.encounterrestaurant.com