About four or five years ago, I was finally able to swing my ultimate monitor setup. 27” 5K iMac in the center and a 27” Thunderbolt Display (2560 x 1440) on both sides. All three wall mounted so I keep all my desk space free. The side displays are angled inward by about 20 degrees. Unlike windows and Linux, which both perpetually don’t seem to care about hi-dpi displays and low-dpi displays in the same desktop, macOS seamlessly handles dragging windows across the entire workspace.

Main task in the main display, docs and other references on the left display and email/messages on the right. Works wonderfully.

I’m so used to this setup that when I go to my real job and am constrained to a single monitor I feel like I’m looking through a periscope at my work.