Take a look at the BenQ G2400W. It's only a TN panel, but for a TN panel it has good color and black levels. Considering you're coming from a TN panel, it shouldn't be that big of a deal anyways. The selling points are low input lag, 1:1 pixel mapping, and cheap price.

It's hard to find a good 24" MVA/PVA monitor right now. You could get a good IPS panel, but it's going to cost ya.