I like most of the Lego Architecture series. I'm not a big fan of the monuments, like the Empire State Building, Big Ben or the Sidney Opera, but I can appreciate their value.
The houses, however, are the most interesting because of the scale. And Villa Savoye—built in the outskirts of Paris in the 1920s—is one of my favorites. Not only the model itself is great, with a minimalist rendering of its interior, but it comes with a book explaining Le Corbusier's building, the epitome of his 'Five Points' construction principles.