TV Options Terrifying Me. Please Help.

Can anyone help a newbie home theatre shopper terrified of making an expensive mistake? While shopping today, I saw a Marantz (40") and Fujitsu flat panel plasma, HD compatible monitors looking quite good with an HD TV signal and a football game. I DIDN'T like the price tag ($15-20,000) or the cases, however, and found something about the screens a bit plasticky. Am I imagining it or is there something also funny and plasticky about the picture, despite the resolution? In addition, the salesman said that for ORDINARY, non HDTV AND DVD, a conventional tube would have a BETTER picture. He recommended Loewe highly, but none were in stock and the $5500, 38" widescreen HDTV is back ordered for at least several weeks. He therefore showed me a $4000, 34" widescreen Panasonic HDTV compatible set which looked quite amazing with some manufacturer's HD demonstration but at that point I was already a little tired and confused. What is really important from your videophile perspective that will give me some insurance against obsolescence? Is there any major benefit to the plasma screens other than size? If I buy a conventional tube, would you recommend a wide screen 16:9 format? Is the Loewe worth the wait or the premium in price to the Panasonic? Or Sony? And as impressive as HDTV demoes seem, will there be any more than about 3 things to watch any time soon? I would really appreciate any advice. Thank you.