Viridian,
You can find useful calculators for SMPTE and THX recommended viewing distances at:
www.hometheater.homestead.com/viewingdistancecalculator.html
You should view the newer Sony LCD XBR units. I believe the old response time problem for watching sports that Swampwalker alludes to is gone, and that LCDs are lighter and use less energy than plasmas. We moved our fine 36 XBR CRT downstairs, where the box looks too big, but a check on its value at Videogon suggests there is no market for big box TVs, so we'll keep it. We tend to keep TVs for over 20 years, and only a last year replaced a pair of 25 XBRs bought in 1979.
db