Memes

I've owned one that was comfortable for all day use (Steelcase Leap V2) and have had chairs provided by work that were similarly comfortable but I also regularly get up and move around.

My favorite chairs ever were these tall stool type office chairs with a ring at the bottom you could put your feet on: They were standing desk height and we all had standing desks. You could sit in them normally or you could scoot forward a little bit and sit kind of like you would on a knee chair. No idea what they were but if I ever get to pick new office furniture, those would be a strong contender.

I might buy that setup for home one day, but I don't think my Steelcase will ever fail me so I'll probably be using that for the rest of my life haha.

Learn to build a good office chair, then start a European chair empire!

Seriously though, maybe look for offices or institutions selling off their old chairs. IDK how it is in Europe, but in America there are auction sites you can use to buy them. If there's something equivalent to Craig's List over there, that might be a good place to look as well. Otherwise, garage sales maybe?

What's your budget?

Plenty of good office chairs available for normal prices in Europe...