I bought a Boss microfiber task chair a couple of months ago and LOVE it.
http://www.shopseating.com/ProductDe...azonproductads
When I got mine, I bought it through Amazon, but a search there now directs you to shopseating.com.
When I was looking for a chair, one of the things I wanted was the ability to raise it higher than most task/office chairs, but not as high as a drafting chair. It needed to do double duty at my sewing table and at my computer desk, which are different heights. This goes up to 22", which is at least 1" higher than most task chairs.
I also did not want leather or faux leather as I find it uncomfortably warm. The microfiber is perfect for me.
This chair is, I think, a discontinued item from BOSS Chairs, so if you are interested, hop on! It's currently listed at $165 w/ free shipping.
Didn't find it in this listing, but I think that someplace I read that the chair is designed for up to 250 lbs. I'd never really thought about it before, but many of the task chairs out there are evidently not made for those of us who are fluffy.