In the US, most non-HDTV was legacy 515-line NTSC (Never Twice Same Color) TV on VHF. Picture quality was often appalling (I shall say nothing about the programme content...
) and was very prone to color shift and interference. Hence a better system was needed!
Whereas in the UK, our 625-line UHF PAL system was considerably better. But RF spectrum hungry. So partly to squeeze more channels on to the air, terrestrial digital TV came along. But it was far from mature (OnDigital...) when launched and even Freeview often has limited coverage and can suffer from pixellation (those little squares).
Satellite TV became popular in the UK due to Sky's clever marketing. Equipment was cheap and subscription costs low. The vastly superior BSB DMAC system failed
due to the fact that it could only offer 5 (or possibly if the Irish DBS channels were used as well, 10) channels. Sky realised that people wanted quantity of choice and the next step was Sky digital.
Sky digital
should be capable of DVD picture quality, which would be all I personally would want. But often the source material is of low quality; however, I'm convinced that they've been squeezing transponder bandwidth to allow more 'adult' and 'shopping' channels. Sky has also increased its subscription costs over the years and now costs nearly £500 per annum
excluding the cost of a TV licence!
Now we come to the plasma/LCD/CRT saga. I have yet to see a plasma or LCD picture as easy on the eye as a good CRT picture. A modern DVD viewed in RGB on a CRT TV is warm, well saturated and has pleasant contrast. Whereas most plasma and LCD pictures are excessively harsh and vivid with extremes of deep black and over saturated colour. Freeview on a LCD screen looks generally pretty awful compared with DVD/RGB/CRT. Or even a good Sky digital picture, from a reasonable transponder.
I consider 'HDTV' to be a very far from mature technology in the UK at the moment - and am in absolutely no rush to move to LCD. But for those who must have wall-sized TVs, don't splash out on anything more than normal Sky digital until the systems have settled down. As for blu-ray or HD DVD......why bother?