Well overall Samsungs seem to be the best tv's out. Their new 650 and 750 Series Tv's are awesome. Sonys are a close second and thats what I currently have. As for longevity, plasma's and LCD's are both rated at 22-27 years under optimal conditions. Look more realistically at 10-15 though. As for an Olevia being a decent TV avoid them at all costs. I have seen them go from having a decent picture to have a muddy one for no reason. Vizio's are a much better choice for around the same price or a Proscan even. As for Burn in it is not possible on an LCD TV, I have never seen it on any computer LCD monitors and the LCD TV technology stems from there. Plasma's can have it and it has been know to happen in as little as two hours, I have seen it personally after 6 hrs. If you get a plasma get some form of protection on it. AS LONG AS IT IS NOT AN EXTENDED MANUFACTURER WARRANTY. No manufacturer warranty covers burn in or any damage caused by it. Read the manual and it will be in bold print. I work at Sears for over a year and was their FT Electronics guy Have talked to their techs and had to deal with manufacturers about warranty work. Trust me its a Pita.
Oh and I voted LCD I've got a Sony KDL46V3000 here 1080P with a 8ms panel and 13.000 :1 dynamic contrast ratio.