My hubby got me an awesome new office chair for christmas this year from Costco. All soft leather and memory foam. I totally love it except it's a little deep and so my short little legs don't touch the ground in it, but I just use a little stool under my desk to fix that. No way I was going to give up that chair!
I've always wanted to try
THIS kind of chair though since it's supposed to be good for core muscles and posture. A woman I used to work with had one the last time I visited and she said she really liked it but that she still went back and forth between it and a regular chair.