Well i can't comment on the Dell and the Asus, because i never used or saw them, i will comment on the screen i just received, the Viewsonic VX2255.
First of all, the screen is so damn bright. i had to lower the contrast and brightness a lot in order to get it to be non eye-straining. The Black finish is a dust magnet.
Second, I can't seem to find out what's it's contrast ratio, the website says 1000:1 but all review sites says 700:1. I am still confused about it.
Until now, i experienced no ghosting whatsoever in games, and i tried it in many games. Movies are excellant on it and are a joy to watch with my surround sound system. and the webcam and mic are a handy extra for me.
P.S. I got this monitor from malaysia for 275$, dunno what's it's price in US.