The Asus PG191 is aimed at gamers, and thus, has loads of extras like an integrated 1.3 megapixel webcam, stereo speakers with a sub, USB ports and mic/headphone jacks. The only feature that was lacking, unfortunately, was the display. Trusted Reviews says:
I found colours to be over-saturated and unnatural and severe banding was also evident. Furthermore, a real gaming monitor would have a widescreen aspect ratio, and all in all I'm not sure it quite does enough to justify its asking price.
Maybe I just haven't played enough PC games lately, but I haven't noticed lots of them being written for the widescreen displays. Xbox 360 games in HD, yes, but PC games, not yet. Otherwise, if you're not too picky about visual quality and like an all-in-one unit with speakers and webcam, the Asus PG191 sounds pretty decent, if pricy.
Asus PG191 Gaming Monitor [Trusted Reviews]