Just a note on LG. I bought a their top of the line THX certified 60 inch Plasma in Nov. 2011. It has a good picture and hasn't had any issues that would even have me contemplate a service call. It's a smart 3D TV that does Netflix, VUDU ect. Can't comment on 3D as I've never used it.
My only complaint is the TV only ever received 1 software update, which came a month or so after I purchased it. Not the end of the world, but Netflix is horribly slow and I've basically stopped using it as I can access Netflix much faster through other sources like our Blu-ray players. The chips they put in TV's to access content are garbage and though they "work" its a complete waste of time to use them. Akin to using a Pentium D computer to try to do graphic design work. It would probably "work", but it would be turrible (Barkley's voice). Add that to the fact it will never see new services or gui's, and it's really a waste.
To Turbo's point, While Apple TV 3 might stop getting updates in the future, it will likely be supported for years. Only 27 months since my TV was new, and LG stopped supporting it about 24 months ago. Panasonic supported my blu-ray player for a year, which was nice, but even it's being left behind.