I'm not sure what we have in the office, but they're the single-vertical-column-with-two-horizontal-arms kind, and the arms have a few joints in them to help angle the monitors.
They might be this:
https://www.ebay.co.uk/itm/234439103851?epid=19031188092&hash=item3695a8d56b:g:3awAAOSwt8Jdr-9G

They're fine EXCEPT that adjusting the height involves loosening a bolt (with an Allen key) and sliding the arm assembly up or down, which is really a two-person job. Not ideal for our hot-desk environment - I've got a selection of favoured desks where the monitors are at the right height for me.

At home I've got two Ergotron Neo-Flex arms, like this:
https://www.ebuyer.com/276499-ergotron-neo-flex-45-174-300-lcd-arm-45-174-300

They're better at being height-adjustable, but can be a bit annoying to get perfectly lined up, especially because I think they're not really designed to be against a wall, which my desk is. They're also not cheap, but that wasn't an issue for me as I acquired them for a nominal charity donation when we moved office (yeah, we had to cheap out on the monitor stands in the new office, but we've now got beer and wine fridges, so it all works out). I suppose you might find office surplus places might have this kind of thing for cheap.

It's probably the sort of thing you really need to try out. (Or at least, watch videos of other people trying out - is Monitor Stand YouTube a thing?)

Is having an easy height adjustable stand something you need?

If that's not a deal breaker, I've had two stands from this brand on Amazon

One was that two armed stand which I've stuck on my WFH desk, and I've had a three armed stand from them for the gaming PC. While both have been rock solid, I'm pretty damned happy with the latter, I've got 3 fairly weighty monitors bolted to it and not a hint of sagging or droopage.

As Kenny said it usually takes an allen key and someone to help to get things aligned properly.

In terms of cost, there's an inflated market price out there for branded kit that has no discernible benefit over the cheaper option (like with most things :C )

How much moving around are you likely to be doing with your screens? Is it a setup that you can leave in situ once it's in place or are you going to be adjusting depending on whatever task you're up to?
 

I've a single monitor stand by 'Invision' and it seems alright in an unremarkable way, I don't think I paid much for it. Stays where I put it, certainly.

I also have 2x Invision mounts - I looked them up and I paid literally £30 for each back in 2017 and they're still fine.

These ones, that are a bit more now:

https://www.amazon.co.uk/dp/B0765Y4CT5/ref=pe_3187911_185740111_TE_item

Piles of books/magazines here.

Ah, I'm on a super-shallow desk at the moment, I needed to get the base up and off there! I used to have my work monitor up on a HTML 4 and a Macromedia Director book to get it up to height, best use I could come up with.

Thanks all! :)

Once height is adjustable initially, it's not something I'll need to change, so one of those T shape ones should be sufficient.

I've got this triple monitor stand.
Wanted it to be stand alone rather than attached to the desk.
It's heavy, chunky and obviously has a lot of adjustment points, but it's good and does the job once you've got it setup. Happily holds 3 x 24" screens

https://www.vonhaus.com/vh_en/triple-monitor-mount-stand