First and foremost, what kind of panel are you looking for?
If you are not gaming on the monitor, then you can go for IPS and VA panels (as they have lower refresh rates). Both these panels have pretty good contrast ratios and color reproduction.
If you are planning to upgrade your setup for multiple monitors in the future, then make sure the monitors support VESA mounting. You can then get a single stand for the multiple monitors. Depending on your preference, you might want a monitor which can be used vertically as well.
BenQ and Acer are amongst best value for money monitors. Dell is a bit more expensive but gives you a premium feel.
I too am researching monitors for programming and here is my shortlist till now: