I've stayed in a few of the hotels on West Century Blvd. Hilton, Marriott, Sheraton Gateway, Radisson ( now The Concourse Hotel ) To be honest not much to choose between them. So unless you have some status with a chain, for such a short stay I'd just go for whatever is the cheapest. Although I've heard The Concourse which is the closest to LAX is looking a little run down now, but I've seen it as low as £35.
All the hotels between The Concourse and Hilton are easily walkable to all LAX terminals if you only have carry on / 1 piece of larger luggage.