I purchased a 47 inch LCD about 6 weeks ago. LED is not quite ready for prime time IMO. Basically it is used for back lighting. Unless the user is a videophile I doubt it would be noticeable in 98% of viewing. Even though I don't watch that much TV, 240hz was important to me for sports. Although my wife watches a fair amount of television it really wouldn't make a difference to her based on her viewing preferences.
I did consider the plasmas, but even with anti glare coating they didn't fare as well as the Toshiba with auto dimming. The room the TV is in is very bright and gets full sun in the afternoon as the windows all face west.
I ended up with a Toshiba Regza. In my case it was clearly my best value. Very happy. The picture quality is very close to my Sony XBR960 CRT. Also considered various Samsung models, which were very good but were not a clear step up from the Toshiba, and cost quite a bit more. Sony seemed a step behind in my size range, but ranked a solid third. Best of all ... I was able to support an independently owned store that price matched. It's our last A/V dedicated store in the metro area.