Plasma is a bit larger and puts off more heat / uses a bit more electricity but is cheaper and generally good picture.
I have a Samsung LED and it works fine. The only thing I dont like about mine is the 60hz refresh rate. If you get an LED, get at least 120hz or you will deal with ghosting.
Plasma is usually about 600hz now I think, so its a non issue. I would just go with a plasma.
I have a 120hz and ghosting still occurs and watching fast sports is still a pain. I am also told 240 hz is not much better
