Although they aren't just one designer, I have to mention Troika as one of my favourites. Troika are Eva Rucki, Conny Freyer and Sebastien Noel, who are widely known for their experimental artworks. Their work is a combination of art, design, science and architecture. They produce work that's highly original based on surreal observations, scenarios and experiences, playing with sound, sight and movement in clever and innovative ways.