An AP article talks about the rise of the antenna with HD TVs. I've set up several HD TVs for people and have been impressed with how well normal rabbit ears work to get a HD signal where it did such a crappy job getting a analog signal.

The article also has a quote from a DirecTV persons stating that their signal is better than anything else even though they compress the signals. I have Dish Network (which does similar things). I'm not complaining about their video quality, it's very good. Sometimes you can tell that the video quality is different. Compression artifacts in fast movement for example, where you dont normally see that on the over the air signals.

Even if you have cable or satellite, I always recommend getting a over the air antenna to receive local channels. Over the air digital TV is that good.