Dell Outlet has their U2414H 24" IPS panel monitors on sale with a coupon for under $200 right now.
http://www.dell.com/learn/us/en/22/...&dgc=IR&cid=260728&lid=4691849&delphi:gr=true
That or some other better quality IPS panel type monitor would be my recommendation. The color and viewing angles on IPS monitors truly makes the older TN type panels look bad. There are also several types of IPS nowadays as well as a couple of other newer types of panels. Also (and not saying you do not know the difference) don't confuse LED with LCD panel types, there is no such thing as an LED monitor, there are LED backlit monitors but an "LED" monitor is still and LCD monitor - LED just refers to how it is internally lit.
If you want to go bigger - also on Dell Outlet is the S2740L which is an IPS type panel is $319 but it is still only 1920x1080. You will probably be looking at newer models to get even higher resolutions but it will either come at a higher price to keep the same image quality or will be sacrificing quality to get the higher resolutions. For example, the U2713HM, also an IPS panel has a native resolution of 2560x1440 which makes a significant difference on how much you can get on screen at once but the cost jumps closer to $600. They also have the P2815Q with a massive 3840x2160 resolution for $600 BUT it is only a TN panel and you might need a new video card to support those ultra HD resolutions.
It ultimately boils down to your budget and balancing what you want (best color ranges of IPS panels or biggest monitor) to fit your budget.