LEGO Star Destroyer -- HA! Malle Hawking beats it hands down. It's a 200,000-brick, 350-pound aircraft carrier -- the USS Harry S Truman -- complete with electrical lights as well as moving elevators and radar dishes.
As all of us geekdads can appreciate, building this model was not without difficulties on the homefront. Hawking, a German father of two and (at least before this masterwork) neophyte bricker spent over $20,000 on parts and it took the better part of a year. But despite "lots of arguments at home" he somehow succeeded and showed the Truman all over Europe. The brick de resistance was to be an appearance at Brickworld '07 with transport provided by the US Navy, but unfortunately the arrangement fell through.