I know its technically still a 'mechanical' keyboard but its not an MX style switch: IMB Model M. I still daily drive one for work even though I can't use some shortcuts (no win/super key) and I have a handful of modern mechanical keyboards at home.
If not that, then probably the one I had for work a few years back, similar era but membrane, unknown brand. It had a little bit of an old smell to it and found it in an abandoned warehouse at work. Left it for my replacement when I left that job.