Since my last, I've removed my classic Macs from my desk, as I have expanded to WAAAAY too many displays. I'm now working from home with a work-provided (Windows) laptop and monitor. And I got a 4K display. Then I got a first-generation 15" Retina MacBook Pro. Which lets me use Thunderbolt "Target Display Mode" with my iMac, and retire my iMac to server status.
So when using my work laptop, I use two 1080p displays plus the 4K display (NOT using the internal LCD, I use it docked with the lid closed.)
When using my iMac, I had been using its internal display plus the 4K display; which it really didn't handle very well.
But now with the new MacBook Pro, with its two Thunderbolt ports plus an HDMI port, I can use it with four displays no problem (internal, iMac-Thunderbolt-Display-Mode, 4K over DisplayPort, and last 1080p over HDMI.)
But, I also have "Duet", the app for iOS that lets you use an iPhone/iPad as an external display. I mostly use it when using my laptop remote, to give it a second display. But just for fun, I hooked it up, too.
Then I realized I have a USB "dock" that uses the DisplayLink protocol to be a passable-frame-rate display output.
So, for this picture, (and only for this picture,) I hooked them all up.
My "normal" usage of the MacBook Pro is either *JUST* the "left three" displays (iMac, 4K, big 1080p) or those three plus its internal display.
I have also since this picture was taken gotten a Logitech K780 keyboard and Logitech MX Anywhere 2S mouse. They support Logitech's "Flow" virtual KVM, where each device can connect to three different devices (iMac, MacBook Pro, work laptop) and if they're on, can switch from one to another by mousing to the edge of a display. (And unlike apps like Mouse Without Borders, it actually tells the devices to switch inputs, so you can have them linked to, say, the work laptop, then mouse over to the iMac, and the keyboard and mouse actually switch to connect directly to the iMac, rather than doing it over network. So I can then shut off the work laptop and they still work with the iMac.)