I recently tried out my Xbox 360 with the monster VGA cables on a 22" LG LCD monitor. I have heard several people complaining about the washed out look the VGA cable provides but I have come to realize that it is the LCD monitor that makes the difference. The below pics are of what gaming looks like in the LCD :
Honestly Gears of War looked great. The last level especially was the best test to see if the colors in the sky look rich and vibrant and I would place them around 80% as good as what I have seen on a Samsung 40" LCD tv. The LG lcd ( L204WT ) has a dynamic contrast ratio of 3000:1 and the dark colors look great in comparison to samsung LCD ( 225BW ) but the main thing is the f-engine which increases the richness of the color and makes the experience more HDTV like.
I also tested a DVD on the monitor. Not sure if its true but the 360 upscales a DVD when using the VGA cable. In effect i get a 720p HDTV upscaled output from a 480p dvd. the following screens are from Star Trek Voyager :
The aspect ratio was fullscreen so i used the 360 to soom in to fill my screen and i could not make out any artifacts at all, its was purely amazing !!!