So you've got an HDTV and an Xbox or PS2, and you want to get the most out of your system. What kind of cables do you use to hook your TV up?
Certainly not the old RF adapter, and no again to the composite video cables that come with the system. Both of these loose to much detail. An S-Video cable would be a good choice, but that won't let you take full advantage of your TV.
Composite video cables are the answer!
The RF adapter compresses all your picture and sound data onto one cable, and that format must match the NTSC broadcast standard that all analog TVs use. You get about 6MHz of bandwidth to fit both the audio and video signal into, which isn't all that bad for 1953.
Composite video separates the audio channels from the video channels, allowing better fidelity for both audio and video.
S-Video is a step above composite video. The video signal is split into into a luminance signal called Y, and a chrominance signal called C. Luminance is how bright the image is, so if you had just the Y information, you'd have black and white TV. In fact, in the US the original black and white TVs used just the Y signal, and there was enough room left over to pack the C signal in when color television came out.
The C signal is specially encoded so that the blue and red signals can be subtracted from the Y signal. When the TV subtracts the two components of the C signal from the Y signal, giving your red, green and blue, the colors that make up the TV signal.
Component video cables separate the C signal into two separate signals, the blue signal minus Y, and the red signal minus Y. This gives you even more room to send color information. Combined, you have much more bandwidth to send picture information. Enough to drive your TV at HDTV resolutions!
I have both the Monster Gamelink PGL400CVAA for PS2 and Monster Gamelink XGL400 CVAA-10 for Xbox. (Monster's website is framed, so they get no link.) Both of these cables are ten feet long and feature analog audio connectors. The XGL400 also has a digital audio out jack in case you have digital-capable audio equipment.
The one thing that bugs me about the cables is that the RCA ends have a very fragile looking cable hooked up to a beefy, tight-grabbing RCA jack. By tight I mean nearly impossible to attach to the TV. Hopefully they're covered under the lifetime warranty if they come apart on you (its happened, but not to me).
I first got the Xbox cable, and it vastly improved the quality of Dead or Alive 3. The backgrounds took on a sharp, nearly photographic appearance and the details of the character's clothing took on such detail that the composite cables made them seem muddy in comparison. This game is featured in 480p, which is still a vast improvement over the 480i signal you get from a composite or S-Video cable. (The Xbox supports 1080i and 720p modes.)
You need to remember to set your Xbox up for HDTV support in the dashboard to take advantage of your cables. Otherwise you'll only have a really clean 480i game. Remember that not every game supports progressive scan modes, with most only supporting 480p, if at all. I do have a list of my Xbox games and which resolutions they support.
I bought the PS2 component video cables second, since the PS2 only supports up to 480p, and the rumors said that the PS2 did not support 480p for DVD playback. Fortunately, the rumors about the DVD playback are not entirely correct. Early edition PS2s only support 480i, but new PS2s support 480p.
Finding the Monster Gamelink cables with analog audio was difficult, because the PS2 also has an optical audio port. Eventually I did manage to track some down.
A surprising amount of my PS2 games support 480p and widescreen mode. Very few games actually advertise the capability on the back of the box, something the Xbox games do mention. The difference in detail is not as large with the PS2 as it was with the Xbox, but 480p games are much cleaner and the textures and polygons all look smoother. The cables are definetly worth the investment.
Just like with the Xbox, you need to adjust the PS2 to get the best out of your new cables. In the PS2 setup menu you need to set both the size of your TV (4:3, 16:9, Widescreen) and the format of the cables (Y-Cr-Cb or RGB). Use "Widescreen" only if you have a 4:3 TV, but want your DVDs to play in a 16:9 frame.
Sony packages its own component video cables with a six foot cord. The cables looked cheaper to me (more like the cheapo Radio Shack headphone cables, always buy the gold ones), but a friend who owned the Gamelink cables had them fall apart on him (literally), so I can't comment on the quality difference.
The Xbox has its own HDTV adapter with a confusing name, the "High Definition AV Pack". (They also provide the "Advanced AV Pack", is advaced better? No! Its S-Video.) Unfortunately the HD AV Pack only provides component RCA connectors and no cable, which means you have to buy the HDTV adapter and an HDTV cable to go along with it. You do get an optical video port with it though.