What is the best desk chair for small spaces?

I got one of those overpriced Herman Miller Aeron chairs at a bankruptcy (for 10% of the new price), removed the arm rests and am super happy with it, no more back pain since I got it and before it was unbearable. It takes a bit of work to set it up properly. This is the 'old' style before they made economy models, it is built like a tank and I fully expect it to outlive me, maybe one day the webbing will need to be replaced but after more than a decade of continuous use I can not see any wear at all other than on the caster surfaces. Keep an eye out for bankruptcy auctions near you and put in lowball offers, if you snag more than one you can always sell it on Ebay at a profit.

1) Serta Essential Mesh Low-Back Computer Desk Task Chair. The lumbar support is adjustable, and the seat is adjustable in height and depth.

https://www.amazon.com/Serta-Essentials-Ergonomic-Low-Back-C...

2) LEMBERI Fabric Padded Desk Chair. It has a padded seat and backrest, and the seat is adjustable in height.

https://www.newegg.com/p/3EB-00B2-000E5?item=9SIBMXKJWA9752

Lastly

3) Have you considered a standing desk?

Bouty makes excellent chair. Looking at their website I'm thinking Arista/Kadera/Fira. The model of chair I have doesn't seem front page but it is the Sity 9002.

The piston gave after 10+ years of service. Contacted them, warranty is for life, they had someone show up and replace it for free.

I would recommend a kneeling chair

IKEA ADDE