very happy with my aeron chair:
im sitting on it right now, have had it for over a year and feels the same to sit on as it did the first day (unlike padded/leather chairs which get worn really quickly with the amount of use I give them).
i got it from some small independent supplier in the UK so probably dont serve your region. they are expensive, but worth it. sure its 3x the expensive of an ordinary comfortable and quality office chair, but it will last more than 3 times longer and imo is more comfy :P