Up until a year or three ago, and for quite a few years I installed custom home cinema systems, including TV's. Personally I would never buy a TV without looking at the picture it produces with the medium you will mostly be using.
Most TV's will have a great picture with a Bluray or DVD fed into it, (as they mostly are while on display), but not be so good with a TV signal, i.e. free-view, free-sat, sky etc. which is probably what most of watch most of the time.
Lesser tv's generally fall down with motion blur (watch a footie match) , a lack of fine detail, inaccurate skin tones, and lack of contrast.
Go to your local TV superstore and, if possible, sit or stand at the distance you will be sat from your TV with your head at the approx height you will be viewing from, grab the remote and have a flick through the channels. some are better than others. you may look like a bit of a muppet but at least you'll find out if you can live with the picture before you part with your hard earned.
If you like the picture add it to your list, if you dont - move on. That and your budget will soon narrow it down to a few.
For Picture quality and reliability Panasonic and Sony would be top of my list, Samsung, Toshiba and maybe LG next.
Another thing to be wary of, don't assume that an xyz37 will be the same picture quality as an xyz42, very often they're not, one may be fab and the other only so so!
So...in short - Watch the exact model TV before you buy it.
hth
