I have a 50" Panasonic Plasma, and I absolutely love it. Everybody has an opinion, and there are pros/cons to both. The picture is absolutely beautiful, and I haven't had a lick of trouble with it. Works fine at this altitude (~5000ft). After the first 100 hours or so, there'* little worry about burn-in. The picture after, like, 60,000 hours, is estimated to be about 1/2 as bright as when new.
By that time this will be ancient technology and I'll be looking for something new anyway.
Best thing to do is go look at different TVs. Beware, however, that most TVs on display have the brightness turned up waaaaaaay too high. On a plasma this will make skin tones look "waxy". Look on the web for reviews of particular brands, some are better than others. I chose Panasonic because of its very high ratings. They're a little more expensive than the bargain basement plasmas, but not as high priced as others.
I have no regrets with my plasma. So there'* a least one experienced vote for plasma, mate.
Whether you choose plasma or LCD, with an electronic purchase of this magnitude, an extended warranty is worth a look IMO.