Ask HN: What kind of chair do you have?

I'm looking to upgrade from my old crappy leather chair which offers no support and causes me to become quite uncomfortable just minutes after sitting down. I'm at the computer 10-12 hours a day so I need to invest in a good chair.

I've heard steelcase chairs and the HM Embody chairs are good, although quite expensive.

So HN, what chair do you have or recommend?