My chair at work was a Herman Miller Celle, which was decent, but I kept hearing good things about the Herman Miller Aeron -- the so-called dotcom boom chair -- and supposedly the most ergonomic chair ever invented. I started doing my research.
Buying one was a more complicated matter. New ones cost north of $1000, which is ok for VC-funded startups but entirely too much for an individual to spend on a chair. Fortunately there are refurbs on Craigslist and such, usually for $400-$600 (avg price is $450). You have to be careful to get the right one though -- there are 3 sizes (picking the right size for your body/height matters), various levels of accessories, generations, etc. (see this video).
I looked for a while and in the process learned that a tricked out used/refurb Aeron was rarer and more expensive than I thought. On Reddit however, folks were talking about an alternative -- the Steelcase Leap V2 -- so I pivoted and went to my local office furniture refurbishers, sat on a few, and decided to get a Leap V2 ($300). I've had mine since July, and paired with a footrest (Amazon), I felt a palpable improvement in my back within days.
My understanding is that the Leap V2 is likely not the most ergonomic Steelcase chair out there (I believe the Gesture is), but I will say it is a great chair at its price point.
I would advise you try out as many chairs as you can before buying -- body shapes are such that the best chair for someone else might not be the best for you. That said, you probably can't go wrong with either Herman Miller or Steelcase.
For me the Leap is less of a gamble, it's much closer to a regular office chair than the Aeron, but still worth the price, it just makes other chairs feel flimsy and still looks brand new after the years I've had it.
Interesting. I managed to buy a barely used Aeron for less than $600. It was pretty easy, although I already knew about the sizing issue.
Have you been able to compare the Leap V2 side by side with the Aeron? I don't think I'm quite ready to trade in my Aeron yet, but, if there's a chair out there that's actually better than the Aeron, then I want to know about it. :-)
I'm not sure if the Leap V2 is actually better than the Aeron but for what I paid for it ($300), it had the armrests and the lumbar support that I was looking for, so I went with it. Aesthetically, the Aeron looks way cooler -- the Leap V2 looks like any other office chair.