When I had my own office, I used MX Blues, Matias Clickies, and a Model M.
Now that I'm in a shared area, I've used Box Royals, Kailh choc clickies (not very loud), Outemu Browns, MX Reds, Zealios, and rubber domes. I used a Model M for a month or two, but I took it home because I felt self-conscious. No one complained, but one coworker joked about it once, and the rest of them are probably just too nice to have said anything.