First off, plug your address into this site:
http://www.antennaweb.org/aw/welcome.aspx
Look for the digital channels. Look at the Frequency Assignment. See if you need UHF (14-69) or VHF (2-13), or both.
See what kind of distances we're talking about, and compass orientation.
The farther you are, the bigger the antenna you need.
If you have a relatively narrow compass orientation, and need only UHF, this is one of the best:
Antennas Direct DB8
I have one, it's awesome.
This one is good as well, though not quite as good (at least in my experience, in my setup, in my location):
ChannelMaster 4228
If you want something smaller, and can mount right on top of your dish, you can get one of these:
Winegard Square Shooter
Put the antenna up first. Then, print this out:
FCC OTA Antenna Regulations
If your HOA comes to you about the antenna, give them a copy.