One quality that is important is VHF capability. Many new so-called "HD" antennas can't pick up VHF frequencies. The longer VHF wavelengths don't work as well indoors either. Add to that the FCC mandated lower power levels, and getting every local channel on one antenna can be a real chore. Since I live right between Madison's two TV antenna masts, only 2 miles away, I get great results from an inexpensive ($30) omnidirectional flat panel antenna that sits unobtrusively on a shelf. I can move it slightly to improve signal strength on one channel, often at the expense of a solid signal on another. With a little patience I found a good compromise, and left it there. If you're more than 5 miles away, check out directional and/or amplified indoor antennas. If you're more than 15 miles away, you're better off with an outdoor antenna. Over the air DTV is the best bargain in TV; it's very high quality, and it's free!