All HDTVs are designed to look good in a store, but that means the generally don't look as good in your home. At least, not how they're set up out of the box. Consider the giant sodium lights in the rafters at Costco or Wal-Mart. They're very nasty places to try to evaluate an HDTV for your living room. Electronics companies know that your eye likes a little more blue in your video than the standard and that this setting also looks good under the sodium lights at the big-box stores, so they send your HDTV ready to sell, not ready to look good in your living room. This is true of LCDs and plasma HDTVs.
Even though EnergyStar-certified displays have a "home" mode, there are still plenty of settings that need to be adjusted for the TV to look its best.
Knowing this, a professional video calibrator is the key to you getting the last drops of performance and a longer life from your next HDTV investment. Mostly trained by the Imaging Science Foundation (ISF) run by Joel Silver, video calibrators have the measurement tools to take your new high-performance video display and make it look its best in your room. THX also offers two courses in video calibration.
If your room has a lot of daylight, they can adjust. If you have a dedicated theater, they can get the best contrast. The difference a professional video calibrator can make is not subtle. Anyone can see the performance difference. You do not need to be a videophile to see what your investment looks like.
Also, a properly calibrated HDTV lasts longer and generally draws less energy, which justifies the cost of the calibration. Most calibrations cost between $300 and $1000, depending on the room and the HDTV. The ISF gladly recommends calibrators in your area.
You can also check out the Video Calibration forum at hometheaterequipment.com.
Though it's not the same as a full calibration, video setup discs like Digital Video Essentials go a long way in getting a TV to look its best.