Sculpted like the spinal column and rib cage, the Teknion RBT (for "responsive back technology") actively supports – by flexing – your changing positions throughout the day. The synchro-tilt mechanism even keeps your back at an optimum angle of 20 degrees. "Ergonomic expression is at the foundation of the design, so it provides superior comfort," says designer Zooey Chu. [From $1,320; teknion.com]