You want to get an LCD with DVI because DVI is digital, meaning it's the native format of your video card. In order to send a signal to a CRT (an analog device), your video card converts its digital signal to analog and sends it out your 15 D-Sub. This can lead to quality loss for one. Now, at first LCD monitors took a normal 15 D-Sub, because video cards didn't have DVI connectors. But LCD monitors are digital devices, so the monitors have their own analog to digital convertor. This means that your video card makes it's signal (digital), converts it to analog, sends it to your LCD, which converts that analog signal to digital. Two conversions, two opportunities for quality degradation. A DVI connector on your video card sends out the pure digital signal to an LCD's DVI connector, meaning there is no signal conversion. Meaning no chance for quality loss (unless you've got a bad cable). Bottom line is you want an LCD and a video card with DVI.