Cable channels like Discovery and History aren't broadcast over the air, so you won't get those with over-the-air HD antennas. You'll get locals, ABC, NBC, CBS, FOX, PBS, the WB, and other independents. Many of the local stations broadcast 2, 3 or more channels. For example, the local NBC on channel 5 might be broadcasting regular NBC stuff on channel 5, and then also be broadcasting additional programming on channel 5.1, 5.2, 5.3, etc. Digital channels have decimals in many cases. Sometimes the additional channels are reruns of new and old TV shows, sometimes it's children's programming, sometimes it's just the live local radar image.
I have Dish Network satellite TV. I used to have a VuCube V-10, but upgraded it to the new
"Tailgater" (similar to a VuCube V-20 or V-2000). The Tailgater is cheaper, by half, than the VuCube (both are made by
King Controls, same as those great big "derby hat" dome antennas), and unlike the old V-10 this one is automatic in that it will located all three satellites (110, 119, 129) so all the HD versions of the channels come in (V-10 only saw 110 and 119, and you had to manually find them).
It requires a Dish Network 211k receiver, as it's the only receiver that has the software for the Tailgater, and, obviously, a subscription to Dish Network. Subscriptions are available for the Tailgater alone, of course, or if you already have Dish at home then all you need is the 211k receiver box ($150) and the Tailgater ($350) and it costs an extra $5 or $10 a month for the second receiver.
I have America's Top 200 along with HBO and Starz. I don't have local channels (ABC, NBC, CBS, Fox) unless I'm within a couple hundred miles from home (within the local spotbeam). So for locals you have two options, one is to connect an over-the-air HD digital antenna to the 211k's HD antenna inputs (the HD tuner is built in to the receiver), or, what I have, is local channels via
All American Direct (My Distant Networks) where I get the locals from both NY and San Francisco directly through the satellite dish. You can get NY or San Fran only, but for not much more you can get both. The neat thing about having both is, if I miss something at 7PM on the east coast feed, I can catch it again three hours later on the west coast feed out of San Francisco.