Re: Which TV?
Buy a decent plasma TV (Panasonic, Pioneer, etc.), hook it up, watch whatever you like on it. The whole burn-in thing is totally an Internet myth. Yes you can permanently burn out pixels on a plasma television but not by playing video games for a few hours here or there and certainly not by watching 4:3 format TV programs. I don't know why people feel the need to propagate this stuff.
It may have been an issue with some very early plasma displays and it is no doubt possible to cause burn-in by displaying aircraft departures or playing a demo loop 24/7 in torch mode. But it just isn't something that happens to people using a television as a television in a normal home environment. All those reports are friend-of-a-friend-saw-it-once sort of stuff.