Don't look for low response time, that's a red herring. Look for low input lag. This will require some research. Stay away from Samsung and Dell which usually have high input lag, also stay away from anything with dynamic contrast which is also associated with high input lag.
Hey, you guys replied to my post which practically has the same subject so I'll post this more than useful link here to you guys: http://www.digitalversus.com
Look for the LCD monitors and you can compare a lot of reviewed monitors head to head per subject (ea contrast, input lag, ghosting etc).
This website will be my holy guideline for the next few days, I hope it will help you too .
GL with your hunt .
You probably read it in my own thread already but I'll still post it here:
the LG 2253V(-PF) for the least ghosting and best colours,
the LG W2261V(-PF) for better contrast and still very little ghosting (do pay attention to the product name of this monitor as there is a monitor called LG W2261VP-PF which has a far worse panel than the V-PF)
Both go for around 180$.