Nearly all the Samsung and Panasonic plasmas will outperform every other TV out there in performance, picture quality and features.
The mentioned Panasonic Ut50 is a great display for movies and games but not for a static desktop. As it is a plasma, it is prone to levels of burn-in.
Basically, as far as burn-in, as long as you are not displaying a static image for longer than 10 minutes you should be alright. Burn-in is no longer the problem it was years ago but it still exists to an extent on plasma panels. On my plasmas for example (Samsung PN51E7000 and Panasonic Viera TC-P50VT25) sometimes the start bar would be visable even after turning the tv off. This would go away after a few minutes but it is something to know when considering a plasma TV.
Also, plamsa displays have a very high refresh rate that no existing LED/LCD can touch.
As for LCD vs LED, LED typically has better and brighter color. The minimum refresh for an LCD/LED should be true 120hz and not the 60hz with motion interpolation like some lower end models that claim 120hz. So read up on that if you decide to go with a LCD/LED.
For the money, the UT50 is hard to beat as long as you dont idle on your desktop.