HDTV offers much better quality than standard NTSC. This image is a reference image showing maximal quality. (Click on the images to watch the unscaled high resolution original)
HDTV content captured via PC receiver cards. (Click on the images to watch the unscaled high resolution originals.)
Still undecided is the HDTV and DVD situation. There are just a few HD DVD players available today - a list of HD capable DVD players can be found at DigiUpdate.Com . NEC and Toshiba developed a new HD-DVD standard that competes with a different standard developed by Sony, Hitachi, LG/Zenith, Matsushita, Pioneer, Philips, Samsung, Sharp und Thomson/RCA. A third standard is Microsoft's HD-WMV9, which can also be implemented in DVD players.
Regarding audio, Dolby Digital 5.1 (AC3) has become the de facto standard for digital TV and DVD.
Cinema at home, thanks to HDTV beamers and 5.1 surround sound.
There's no limit, assuming there's also no limit to your budget.
The entrance into surround sound is not expensive - here we see the Pioneer HTP240 for less than $300.
In contrast to TV standards, audio devices used worldwide are compatible with each other. The only factor is the different operating voltages (110 V vs. 220 V).