I'm using the Pinnacle TV for Mac HD Stick. I got it at Worst Buy at their semi-annual, actual good sale price of $80. I think it's usually $120.
I LOVE this thing. It's the size of a flash drive with a coax jack stuck to the rear, and it flawlessly pulls in all the local stations I could ask for. I do have a nice aerial on the roof that I installed for my main home theater system, so that helps a lot. I can't speak to how well it would do with rabbit ears. The HD Stick, in conjunction with my new 24" iMac, makes it easy to see how one could really simplify things and ditch the big HT system and just watch TV and movies on the Mac. The ElGato EyeTV software is very Apple-like, and it has so far worked without a hitch. I did spring for the upgrade to the full version from Lite that was provided with the tuner stick.
From my 5-ish years of HDTV ownership experience, there is no HD signal like a local, off-the-air HD signal. They don't have to compress the signal like the cable and sat companies do. To see a nature show on PBS or a big-dollar network show in HD on the 24" screen is really something.
The EyeTV software has quick buttons to export video to different intents, and I've used the 'AppleTV' export function and it works great. The shows pop up in iTunes with their metadata intact and work fine with FrontRow, etc....
As I mentioned before, I love this thing. I didn't know what to expect, but the combination of an excellent tuner and an excellent LCD display is drool-inducing.