I had a feeling people would be split on this topic.
How about these Aeron chair's? Anyone have one?
Amazon.com: Aeron Chair - Highly Adjustable Graphite Frame w/ Lumbar Pad - Carbon Classic (Medium) by Herman Miller: Home & Garden
I have read threads in other forums discussing this chair thouroughly and the overall impression that I got was that once they are adjusted perfectly and your body gets used to it this is the finest chair ever made.