I want to thank you all for taking time to post a reply to my question.
My husband is in agreement with those of you who feel that Disneyland is a must for a 6 year old visiting LA, so off to Disneyland we go. Oddly enough my mother who is definitely a "shop-till-you-drop" type also insisted that we take my son, and claims that she will just sit on benches for long stretches. This should be interesting.
We are going to be there Monday till Thursday and will definitely visit a few of the places mentioned by posters.
I'll be sure to post to this thread upon our return.