I'm dabbling a bit with cctvs and this is one problem that i couldnt solve till now.

I have tried swapping cameras and cards (silicon and a locally made dvr card) but to no avail. Switching between 800 x 600 and 1024x768 didnt have much impact that's noticeable.

Is there anyway to replicate tv image quality on a computer monitor?

Unfortunately in most cases when using a VGA output you will not get as good as picture on the computer monitor as you would on a composite video monitor. Try setting the DVR resolution to it's highest resolution and biggest picture size and that might help, although it will also use up more hard drive space.

You'll find that embedded systems that use composite video outputs instead of VGA outputs almost always show better. I'm not sure of the technical reason for this but I'll bet that someone here can give a more detailed explanation as to why the digital picture just doesn't give you the same sharpness and contrast as a composite/analog picture.