The Emmy-nominated home-renovation series has gone from cult favorite to breakout hit. The setup: Two pairs of friends swap houses and work with a designer and a carpenter for two days to remodel a room on a set budget, with a bubbly host overseeing the proceedings. Of course, some results are more sensational than others, and that's part of the fun in this much-imitated series. 'Trading Spaces' and its two spin-offs ('Boys vs. Girls' and 'Family') are based on the British show 'Changing Rooms.'