The best chair I ever had was from Knoll. But they're expensive. The one I had was priced at $1000 USD. The company I worked for obtained them when they leased space and the company they leased from sold all of the furniture to them for $1 USD. Yes, you read that right. I offered to pay twice what they paid when I left just to take my chair with me. LOL! (They gave it to me for free.) It lasted a few more years before the arms finally broke down and replacements were hard to come by as the particular chair was discontinued.
I looked for quite a while for another chair to replace it. It had to fit me okay. I'm a smaller size, so it had to raise up and down a good length so I could type comfortably and not cause the shoulder pain I get when my arms aren't at the right position, and it had to have and independent back rest such that when I lean back, the seat doesn't lean with me. It also had to have a rating of 8+ hours for working. I found several that fit my criteria, but the prices were too high. One day, I lucked out and found one at a local office store on sale for a $99 USD (normally $199, which I would have been happy to spend... was willing to go up to $399) and it was just what I was looking for. I've been very happy with it. This is what I ended up with: