No matter what kind of TV you have, chances are it could benefit from it quick little calibration. The method I'm about to show you doesn't require any special tools, just a DVD player and the THX Optimizer, a small calibration tool found on a number of movies. Odds are, you already own a DVD with it. All Pixar and Star Wars movies have the THX Optimizer. For a complete list, go to: http://www.thx.com/home/dvd/search.html and hit "view the entire list"
Usually, the THX optimizer is in the Setup or options section of the DVD menu. Once you find it, run through the video calibration screens, adjusting everything as they describe.
Before you begin calibration, I'd recommend you set your TV to it's factory settings or "normal" mode and keep the color temperature at "normal." Then, get the set calibrated. After calibration, write down the setting values for future reference. Note: if you have an older set with a hidden panel and knobs, get the knobs to their default position (where they kind of "click") then work from there.
After running the THX optimizer, I'd recommend you tweak the color control a tiny bit to get the flesh tones just right. Also, if your TV is connected to a source via composite (yellow jack), it probably has some "dot crawl." I find that the effects of dot crawl can be minimized when your sharpness control is at or below the default. Sit at your normal viewing position and pull up DVD player settings menu or other static image, then tweak it. Afterwords, turn on sports or something with fast action and fine detail as a second test.
Some TVs (especially older ones) could also benefit from a tint control calibration. If your colors are off and un-natural after calibration, you probably need it. Bring up the calibration screen with the white squares and adjust until those squares are really white. Afterwords, look at flesh tones and make sure they look natural.
If you did everything right, you should now have a picture with high contrast (black is really black), natural colors (not too intense) and a sharp, bleed free picture.
Note: if your TV has a different setting for each input, get them all to your calibrated values. For VCRs, you probably want to turn up the color just a tad. For Component, S-Video and DVI/HDMI inputs, leave the sharpness at normal. For Composite and RF-modulated, turn the sharpness down a bit to minimize dot crawl (as previously stated).