I've seen a lot of people that have high definition televisions and their picture looks like crap. It's either cropped or it's a low def picture stretched out across the whole screen.
You haven't really seen a good high definition TV in action until you've seen a true HD channel received via an antenna.
Antenna? No one uses an antenna!
That's sad but true. Most people already have cable or satellite and just hook there nice HDTV up to it. The problem is that few people actually get it set up correctly and pay the extra money for the HD feed. Thus, their image looks like crap.
Even when watching DVDs you have to know what you're doing. Although their are HD Bluray players, an upconverting normal DVD player will give an amazing picture, but only if you configure the DVD player and the set correctly. For a couple days I watched a cropped picture until I found out how to set the DVD players aspect ratio to the correct 16:9 setting.
If you have a true HDTV, try hooking up a tv antenna to it. You can go to this site in order to find out what stations you may be able to receive. [Note: the site is very good and legitamate--just don't enter any of the non-required fields and you won't get any ads from them.] It does not have to be a fancy HDTV antenna--older antennas will work. Once you see a true HD image from a true HD over the air signal you won't believe how good it looks.
The image above is an outdoor UHF antenna that I've recently purchased to use for receiving HDTV signals over the air....