Like many children, both of my boys are pretty obsessed with LEGO. They have been playing with it for a few years, and it was starting to take over. We had pieces in their bedrooms, family room and living room. Sets put together in their rooms, and on the floor in front of our fireplace (not to worry, we never use it - no chance of LEGO melting).
We realized we needed to do something as LEGO was quickly taking over our house. Hubby went to IKEA and bought 2 Trofast storage systems as well as bins to go with them. He then picked up a sheet of MDF at home depot. Once they decided how big to build the table, hubby positioned the storage units and cut the MDF to fit on top of them. It's quite a long table, so there is a unit on either end of the table for stability.
After it was put together, Mr. J got to work adding his pieces to the table to build his city. The bins hold his extra lego pieces and fit perfectly in the Trofast units. Underneath there is a small "tunnel" that he can crawl through to get to the back, or to access the storage bins.
And here it is! What his city looks like now. He adds to it and changes things around whenever the mood strikes!