I have the Samsung S23A700D and it's the best for gaming.
I find that the Asus monitors have poor image quality. The color reproduction is bad. The only positive I can give the Asus monitors is the responsiveness but I didn't really notice a difference between the 1ms Asus monitor to the Samsung S23A700D side-by-side when I tested it with a friend.
The Samsung S23A700D or any other Samsung 120Hz monitor gives the perfect balance between color reproduction, image quality and responsiveness.
If you're looking to spend no more than $200 then the Samsung S23B300B is better than the Asus VS239H-P.
http://www.newegg.com/Product/Produc...82E16824001546
The LG EB2442T-BN is also very good:
http://www.newegg.com/Product/Produc...82E16824005344
I've worked in the computer display industry before so I know the difference between each company in terms of which panels they use.
If there's no limit to your budget, why not get 3 27" monitors? The Dell U2713HM is probably your best bet when it comes to image quality and color reproduction. They use IPS (in-plane switching) panels which is superior over standard LCD. Or you could get the Korean IPS monitors which give basically the same quality as the Dell U2713HM.