Here is a fun and completely different chair that has endured the test of time. The Pastil chair from Eero Aarnio was designed in 1967 as an after thought of the famous Ball Chair. According to Aarnio " a lot of empty space is sent to the other side of the world inside the Ball Chair.
A new round chair would fit in this space, and so the diameter of the Pastil chair is the same as the opening of the Ball Chair". Upon its release the Pastil received the American Industrial Design Award and was hailed as "the most comfortable form to hold up the human body" by the New York Times. Today this all fiberglass form is produced by Adelta in Finland and is available from hivemodern.com for $1695. 36.5" dia. 20.5" h