One of these days I am going to have the funds and the time to get to one of the Lego theme parks.
A simple question for you. Which one is best?
Given that a departure point from Australia means none are really more geographically convenient. Where should I take the kids?
My suggestion would be to visit LEGOLAND Carlsbad in California. The park is open year round and weather usually will be nice. In addition, you would be relatively close to Disneyland which the kids would enjoy.
The other advantage is the lower value of the dollar could allow you to purchase more. Prices of LEGO sets are very reasonable in the USA. You could pick up a few sets for yourself on the trip.
The other option is to go all out and travel to Billund for the LEGO Inside Tour. This tour is expensive but an extremely rewarding experience for fans and their families. Check out the details here: http://www.lego.com/eng/info/?page=eventdetailed