The Wii is part of the next generation console trio along with the XBox 360 and the PS3. Just how does its graphics compare?
First, by this point most gamers have seen an XBox 360 in action, even if they don't own one. In fact, many people bought high definition TVs primarily to play XBox 360 games. If you've seen a game like Oblivion on a high def TV, you know that the graphics can be *gorgeous*. Sunsets in the game Gun are also an example of truly pretty visuals.
In comparison, a Wii provides output for component (red/yellow/green cables), composite (a single yellow cable paired with a red/white stereo signal for sound), and S-video (sort of like a circular computer keyboard jack). If these all is Greek to you, follow the link at the bottom for photos and information on types of cabling.
The Wii only outputs a signal of 480p, that is DVD quality. That means you are seeing better than what a "normal" TV can handle, but not as good as a high definition TV can handle. The Wii comes with composite cables. These are the red / white / yellow cables that most VHS units come with. Unfortunately, if you have a high definition TV, a composite cable can ONLY carry a signal meant for a regular TV. That means you won't even see DVD quality graphics from your Wii - you'll see basic TV level graphics. You'll want to buy a component or S-video style connector for your high definition TV, to be able to see the full DVD quality level.
When you consider that a HUGE draw for the Wii is its ability to play all GameCube, Nintendo 64 and other older games, and all of those games were optimized for standard TV signal graphics, you'll see that this really isn't a big issue for most gamers. Only the brand new games that come out will be able to be higher quality, and those will be DVD quality. The world has loved and appreciated DVD quality for quite a while now!
That being said, it's important to understand this difference so you can compare apples to apples. Yes, the Wii is "lower quality" compared with the XBox 360 and the PS3. But since the Wii can't play DVDs anyway, of any kind, and since it's less than half the price of the other two units, that's really not that bad of a trade-off.
Composite, Component and S-Video Descriptions