LG's C2 OLEDs are brilliant gaming displays at any size - and the 42-in and 48-in models are just small enough to fit onto an average to large-sized desk. That technically makes them "cool gaming monitors" and therefore well within my RPS deals duties. Both are now discounted from Crampton & Moore via Ebay, with a 25% off coupon ("FLASH25") that maxes out at a pretty sweet £150 discount.
That means you can pick up the 42-in for £779 and the 48-in model for £848, both of which are the best prices we've ever seen for these highly recommended TVs.
Over at Digital Foundry, where 4K TVs are well within our wheelhouse, we actually recommend the LG C2 as 'the best gaming TV' - and it also ranks highly as a monitor in these relatively smaller sizes. Speaking frankly, even 42 inches diagonally is a pretty massive screen that requires a deep-ish desk and a short adjustment period, but in exchange you get one of the best displays available and a deep list of gaming features applicable to both PC and consoles.
First: that screen. OLED panels offer near-instant pixel response times, gorgeous colours and perfect blacks for technically infinite contrast. This enhances a wide range of content, but just speaking of gaming you get impactful HDR - brilliant for recent games mastered for it, and older models enhanced by Windows AutoHDR - and excellent motion handling that is ideal for any kind of fast motion. This makes the C2 a great all-rounder in terms of gaming, and of course is handy for other pursuits like films and TVs and whatnot.
Next: gaming features. The C2 supports both FreeSync and G-Sync (and generic VESA slash HDMI Forum VRR), so you're well covered in terms of PC-specific features. There aren't game genre specific modes or cheating-style crosshairs, but these arguably aren't that important anyway - in my book at least. Unlike gaming monitors though, this TV has a TV built in, so you can do things like watch TV, or Netflix, or whatnot. There's also HDMI 2.1 on all four ports, so you can connect to PCs with modern graphics cards at 4K 120Hz as well as current-gen games consoles like PS5 and Series X.
Any downsides to using the LG C2 OLED as a monitor? As always, there are some things you should know about. First, it's technically possible to suffer from permanent image retention, aka burn in, where pixels lose the ability to shift and you can see faint afterimages where bright static content has been on-screen for extended periods. For example, you might want to hide your taskbar if you spend a lot of time at the Windows desktop, or go for a darker background. Modern OLEDs have a lot of countermeasures to prevent this, like dimming static elements and electronically massaging the pixels when the display is off, so I personally wouldn't be worried - but you should research the issue yourself and make your own mind up. Secondly, the LG C2 uses a non-standard pixel grid, so text doesn't look as clear up-close as it ought to. There is software to correct this and is unlikely to bother you, but again, you should have a look at some examples online and see what you think. I don't think either of these are dealbreakers, and I've known quite a few people to use these OLEDs as desktop monitors without issue, but YMMV, caveat emptor, etc.
So altogether, the C2 is a surprisingly good monitor, if you can stand the size - and at these prices, these are actually less expensive than similarly-specced gaming monitors, which can run into the four figures for an oftentimes worse HDR experience. Pound for pound, I reckon it's the best gaming monitor you can find for three figures, so take a look at some reviews, weigh up the prices and make your mind up!
If you have any questions, I'll be chilling down in the comments.