I kid you not. What could be more delightful that constructing your very own lego version of the "Fallingwater" house in Pennsylvania?
The kits were designed by Adam Reed Tucker in collaboration with Lego. See the website here.
Other options include:
And the Empire State Building, which I find a little underwhelming.
All images via the Brickstructures website.
I found out about these via 'A Daily Dose of Architecture.'