Is a digital monitor with DVI worth it?

Hi guys. I have a few questions about monitors before I buy one.

I recently got a new PC, spec below:

Core 2 Duo E6600 @ 2.4Ghz
2GB Samsung DDR2 SDRAM @ 667Mhz
nVidia GeForce 7950GX2
Hauppauge WinTV-PVR150
Windows XP MCE

It's mostly used for games, and MediaCenter (live TV, etc). I'm still using my old 19" LCD analog monitor with it. My gfx card has 2 DVI outputs, and no VGA ones, but it came with a little DVI-VGA adapter to let me use my old monitor.

My questions are:

1) Is it worth getting a DVI-capable LCD monitor, for games/video/etc?

2) If so, is Response Time a big deal? Most cheap DVI 19" monitors seem to be 16ms or 8ms. I've seen an LG one with 5ms, and a Viewsonic with 2ms

3) Is Contrast Ratio a bigger deal than Response Time? The one with 2ms response time I seen had a 250:1 CR. The one with 5ms had 800:1.

4) Would such a monitor technically mean I could watch HD?

5) Any recommendations for a DVI 19", not widescreen?

Thanks guys