LEGO’s largest set ever: The Titanic
Achshully, if we are going by piece count, that would be the 11,695 piece world map. 
Still it impressively edges out the now third largest 9,036 piece Colosseum, and dwarfs the largest Star Wars set, the 7,541 piece Falcon.
My largest is the 75060 Slave I at 1996 pieces.
