My primary monitor has recently died, and my backup is showing it's age. I need to buy a new one and am trying to decide what to buy.

I only want to spend a few hundred dollars and to work with my Linux laptop, and be as large as practicable. I'm coming from a 21.5 inch monitor, and in this price range it looks like a 24 inch or 27 inch fit.

I found the Cnet buying guide and Tom's Hardware Guide useful for understanding what to look for.

One factor to consider is the pixel density; ideally it's around 90-110 PPI (Pixels Per Inch). For a 24 inch monitor at Full HD (1080p) it's 92 PPI which is just on the low side of the range. For a 27 inch monitor at Full HD it's 82 PPI, which is on the low side - some people say it's alright, some say it's hard to read text. A 27 inch monitor at QHD (1440p) it's at 108 PPI which is back in the managable zone. I'd play it safe and stay above 90 PPI.

The low end of a 27 inch QHD monitor is a Panasonic 272B8QJEB which is a bit under $400. This is a pretty featureful monitor with lots of connectors (HDMI, DVI, VGA, Display Port), and a VESA mount. One slight concern I have is whether my old Linux laptop will handle this monitor properly; I think it will, but it's a risk. For a 24 inch HD monitor there are lots of options around the$200 mark. I know my laptop can handle 2 external monitors with xrandr, so it seems like 2 x 24 inch monitors would be a better choice for the same price. Otherwise I could get a single monitor and just work with 20% less screen real estate.

Having lots of options is hard; I end up with analysis paralysis - I have a maximising mindset. I thought a bit about connectors, but really ended up filtering by known brand and sorting by price.