Having done the tour de States once or twice I would recommend a few places and give the pro's and cons.
San Francisco
I'd definitely recommend San Francisco. Alcatraz is a great tour and lots of fun (as long as you don't mind a short boat ride) and has lots of fantastic seafood restaurants. I would not recommend you stay in Fisherman's Wharf though. It's a bit like Southend on Sea these days and very commercial. I'd also recommend San Fran as a hub to get you to places like Yosemite National Park. It's a must do day out IMHO. Just the most beautiful place. The problem with that would be the time of year. Yosemite might still be quite seriously impassable in some places and you wouldn't see it at its best. Worth checking out though if you fancy. However, from San Fran you can also visit the Napa Valley and do the wine tasting tours.
Los Angeles
The pro's are great family day out places like Disney Land, California (which is much smaller than Disney World Orlando) and Universal Studio's, California which is absolutely fabulous! (dahling!)
You're also within a couple of hours drive of my very favourite place in the US - San Diego. Just the most stunning town and home of the world famous San Diego Zoo. Trust me when I say this is the best zoo in the world and I loved every minute of it. Not generally a great fan of zoo's but this place is doing so much good work!!!!
The downside of LA for me was the strip itself. I never felt safe there although it was very interesting to do the walk of fame reading all the famous signatures and Mann's Chinese Theatre.
It will be warm though!
Orlando
Non stop fun! If you decide on Orlando you'll not be disappointed. It is VERY plastic. Every person in every restaurant you go to will tell you to 'have a nice day' and there must be more body fat per capita wandering round Orlando than there is in any other place on the planet.
It's very false but then so is Vegas and a holiday should be an escape from reality. You've got the obvious attractions - Disney World, Wet and Wild, Universal Studio's etc but Disney also have two huge water parks, a downtown area for food and entertainment at night, their own animal park and Universal now have their Islands of Adventure (which I haven't been to yet - darn!). There's also Old Street which is an evening entertainment place with fairground rides etc. Well worth a visit if you've never been.
Also, will be nice and warm.
New York
I love New York but i'm not sure (and this will probably sound daft) if it's a place for a large family to be wandering around. To my mind NY's a place you go with your other half and just enjoy mooching around whilst everyone around you is making a mad dash from A to B. Just my personal opinion though. Attractions in NY are obvious so i'll not insult your intelligence by going through them but it's a wonderful town - can be done after Las Vegas and makes the jet lag a little more bearable when you get back to the UK as there's less time delay.
However, it will be feckin freezing!
The only other place I would recommend would be New England/Boston etc. Boston's a bit like NY but with a real English sort of air to it. Home of the Boston Tea Party and some really nice places to go and visit. Very nice if you just want to mooch around and take in all the old buildings. Quincy Market is a must - looks very much like Covent Garden and is a hive of activity with street performers and the like. Personally I wouldn't do Boston for more than 3 days as I don't think there's enough to do there for your average person. Our friends went further into New England and had a fantastic time though so I suppose it depends on where you end up there.
Good luck with your decision P. Was talking to Jac about getting together for some lunch soon so if you fancy you're welcome to join us and we can dissect things over a bottle of wine (or 6)
