Get something with 8ms response time or lower. 3ms or 4ms is even better, but at 8ms you wont notice ghosting. Makes sure it has a 600:1 contrast ratio or higher as well.
the vx924 is very appealing to me, however its lack of ability to lower really turns me away.. the place where my monitor sits is already 4" above my desk and i'm afraid this monitor will be too high up for me....