I'm going through the same TV buying quandary at the moment too Rich. Ironically, working in the TV & Film business I still have my old steam driven CRT Panasonic which has stood the test of time these past 12 years and doesn't appear to be failing in any way! HD Smart Tv's are fast becoming the must have TV's of today and I feel I'm missing something when I actually sit down to watch the dross that I've probably worked on.
Technically, the proper back lit LED screen's are the cutting edge right now although I've seen some newer Plasma's that are much richer and more film-like than the LCD/LED sets but very soon the OLED (Organic Light Emitting Diode) screens will be within reach, probably first from Samsung, Sony and LG followed by Panasonic et al. We use an Sony OLED as a monitor and I'm very impressed with it at 7 inches but will reserve judgement until we see the larger sizes. If I'm being totally honest, most of my movie watching is at the cinema and my small living room won't allow a big set. A friend has a good JVC projector set up and providing its dark, a beer in hand, his projector driven home cinema is the finest I've seen outside Leicester Square! Not everyone has the space for such a piece of kit so my advice is similar to PDT''s; definitely demo some equipment at a Richer Sounds or Graham's HiFi and remember the PC World/ Curry's outlets staff generally have absolutely no clue about anything, nor is the layout of the TV's in long rows going to help you pick a good 'un. You needs to be at least 2m from a 40 inch set;more for a 50 incher. I'll wager you'll not find anywhere with that optimum distance.
Let me know how you get on
PR