I watch Digital TV off-air in Los Angeles and this is how I do it.

Low Rez Table and Screen Pix

--The screen is a ViewSonic VP2130b which appears to be discontinued. It has the
sweet spot of good black level, motion, brightness, color balance, and quality. There
is a backlog and some suppliers, like CDW, are expecing another shipment. We'll see.

--Mac Mini. DuoCore Intel 1.83 GHz with 2G memory.
The DVI connection is required for good theatrical motion.
This is pretty much the smallest machine that will do this.
It's bumping right on the bottom of the EyeTV requirements.

--The tuner is an EyeTV Hybrid connected to a simple roof antenna.
I have a clear shot to Mt. Wilson and all the Los Angeles TV channels.

Antenna Picture

Even with all that, I still have trouble with some channels.

--The device on top of the Mini is a 3/4 TeraByte Seagate FireWire drive.
That's where my Rosemary and Thyme and Doctor Who collections live.

--The two speakers are Boston Acoustic CR6s (original design). Their claim to fame
is a very smooth, pleasant sound and slightly weak bass. This is largely irrelevant because
of the KLH bass cabinet under the table. There is also a 250W rock crusher BGW amplifier
down there running the Bostons.

--And yes, the Latin Grammy Awards are very impressive on this system.
No surround...yet. I have most of the parts.

--The EyeTV software allows Tivo-ing TV shows in any resolution.
The illustration is a CSI-Miami 1080 29.97 HiDef episode from the hard drive.

--I can watch a show on the hard drive while I'm recording something else,
and I can watch what I'm recording (and rewind) but I can't watch one off-air show
and record another. This will be taken care of by the new EyeTV Diversity with
two tuners and antennas.

--Update 20080209. EyeTV Diversity is not available for the US. Only Europe and Australia.

--Update 20090101. EyeTV Hybrid is no longer available because there is no more analog broadcasting

--The room has been toned down in the picture to get rid of the camera's flash flare, but Calleigh
Duquesne (Emily Procter) really does look like that (Click the image).
At night the screen black levels go down to normal and the pictures are very impressive.