My desktop has a 32" in the middle and a 27" either side, one in portrait for reading docs. Though some people screw that idea by showing a menu over a 1/3-1/2 of the width of the page and shrinking the content.
Need* at least three monitors for when I’m doing SCADA + PLC work.
All HP Z series which look pretty slick.
Nomading in Thailand with a Dell XPS 15 and an external monitor powered by usbc, Asus Zenscreen. Both screens are 15.6 matte and both devices are lifted up by Nexstand stands.
Nice one Mathieu!! I’ve been toying with the idea myself and recently posted a thread about it on Devtalk: Digital Nomad Developers - General Dev Chat - Devtalk (you should drop by and share your experience 
)
Desktop, single monitor here. Replaced a dual monitor setup with a single 49" curved ultrawide (5120 x 1440) recently.
Very happy with the format. To get the content I wanted available at a resolution I could see, my dual monitor setup required a fair amount of vertical height. As I wear progressive lenses and am too stubborn to buy a set of dedicated computer glasses, I had a lot of neck strain looking up to the tops of those monitors while getting them into the correct part of my lenses for focus. The ultrawide suggestion came in from someone on Hacker News and trading vertical pixels for horizontal pixels has pretty much solved the neck strain issue.
I develop on a Windows laptop with Ubuntu WSL for the dev environment and Docker for Windows.
The current setup is a standing desk with a 27" 4k Dell monitor on a vesa mount arm in the centre at 100% scale, and the laptop is closed behind it. Layout is usually split in 3rds with code and integrated terminal in the centre, documentation and reference material on the left, and webapp frontend on the right.
I used to work with the laptop as a secondary display but over time my neck and shoulders started giving troubles, so now a mostly dead centre position is best.
Don’t know how you guys do it with the extra wides and multi >27", my neck hurts just thinking about it! 
Dual monitors - 1920 x 1080 landscape. Works for desktops & laptops. Cheap, readily available, future proof. I’ve had good experience with ASUS zenscreen as second monitor for the laptop.
Still searching for a really great mechanical keyboard that connects via bluetooth…
For those of you interested in optimising workspace you might be interested in Andrew Hubermans podcast about it. (I summarised some of it on DT: Andrew Huberman Podcasts - #5 by AstonJ - Health & Diet - Devtalk).
Thanks very much for the link I’ll make some time for it later, just from the show notes I can already see it’s going to be good.
They link to this great study on standing desks https://www.mdpi.com/1660-4601/18/21/11604
The results indicate that the intervention group significantly decreased their sitting time at work (p = 0.002) and had reduced neck and shoulder pain (p = 0.001). There was a significant increase in subjective health (p = 0.002), vitality in work-related engagement (p < 0.001), and self-rated work performance over a four-week period (p = 0.017)
And regarding this one, The Influence of Ceiling Height: The Effect of Priming on the Type of Processing That People Use, I work from home with tons of natural light and a 4m ceiling, which correlates to the feeling of freedom and creativity that I need in this current systems design phase.
Interesting stuff!
This should give you an idea
I generally don’t go reaching for the lower one but what always gets me is if I’m running iPhone simulator, then I’m forever reaching to touch it 
I do have a sit/stand desk which I use at 3 heights,
https://salli.com/tuotevalitsin/)