Whats the most Minecrafty-looking building you've ever seen?

Government center, Boston MA.

Notch's house:

I haven't seen it in person but the mud hut in this video came to mind:

https://www.youtube.com/watch?v=o6Z0MxWCbrc

Habitat 67 in Montréal, built for Canada's centennial and the World Expo.