These days I seem to spend much of my time - and most of my non-gaming time - using a portrait-mode monitor. It's just so much more convenient when browsing forums like this one and websites like [H], reading documents, and when working in Word and similar. Really, for anything text-based. And also for casual Youtube use, funnily enough: those annoying adverts which would otherwise cover the bottom of the video get pushed to the bottom of the screen. Excel obviously prefers the landscape monitor. Websites can look very peculiar on my 4K monitor with huge adverts either side.
How about you?
How about you?