I think that one's a bit difficult as I think it's pretty much a lucky dip. I had 2 Dell screens exactly the same once but one had even colour and the other was rubbish.
I do know a fair bit about monitors and I know what I 'should' look for, but I also know LED displays are fairly new so don't know much about them.
Anyway, in particular, I am asking about PVA CCFL panel vs a TN LED panel, opinions regarding this would be helpful.