Emmet's Apartment from The LEGO Movie
It might almost seem obvious, but one of the most appealing aspects of The LEGO Movie was the care and detail that went into the less action-oriented sets, like Emmet's Apartment. This was where he actually lived,and it is the perfect backdrop for all sorts of additional creativity and play. My son and I carefully took pictures of the paused movie when it came out on DVD, counted out bricks to get dimensions, and drew floor-plans to figure out how it all worked.
We feel this version is about 90% accurate, though some details were not clearly shown in the movie (like the sink and toilet in his bathroom). We added items or details that make his place more realistic to live in, like additional kitchen cabinets, a record player, etc. Some details were simplified, like the crown mould on the walls. Posters and wall pictures were approximated from movie stills.
The front wall of the living room is removable to better see what is inside, as well as allowing one to change things around. Overall it was a lot of fun to build, was educational for my son to learn some more about architecture, and we feel so many others out there would love it too, especially since it would appeal to both boys and girls.