HDMI or VGA? HDMI is a clusterfuck that serves only big copyright holders (and not well). All the hardware and software have to be one happy family for it to work. If it doesn't work through VGA either, then I don't know what's up.
W7RE, lag is not just a function of panel response time. That's 8 ms or less on anything worth buying. The bigger issue is the delay introduced by processing the image so it looks good on the fixed-pixel display. I have a related story. I helped Sandy buy a couple of Vizio LCDs. The first was a 19" for the kitchen. Her kitchen is near her den, and you can hear that TV in the den, where an old CRT TV sat (before we replaced that with a 42" plasma). When tuning both TVs to the same analog cable channel, there's a disturbingly long echo. I don't mean an ambient-type echo, but more like a PA-system-like echo. You hear one, then a long fraction of a second later, you hear the other. That's the processing delay in the LCD TV.* For TV channels, movies, etc, it doesn't matter, because they're not interactive. So it makes sense that the software would put time and effort into polishing the display as much as possible. But for real-time games, that's a joy killer.
(BTW, the plasma-TV's delay is about the same as the LCD's. We can have both TVs tuned to the same analog or digital channel now.)
* And of course, the audio gets the same delay added to keep in sync with the picture.
