You'll find that the question about whether or not extended warranties are worth it can produce some pretty polarizing opinions here . A lot will be of the opinion that TVs are somehow infallible, and that when it comes to these race-to-the-bottom sets, failure simply isn't an option; it just doesn't happen and plans aren;t worth buying.
In truth, yes, flat panel TVs are, in general, pretty reliable and should not give you issue. If the plan is available at a reasonable price I don't see the harm in having it. People often think of an extended warranty as only being useful in the case of a part failure that renders the TV unusable, but I think they become really useful when you think about issues that may arise with the panel that hinder the viewing experience.
Case in point: I purchased a 55" Panasonic VT50 in May of 2012 with BB's 4-year plan and by last November, had noticed that the TV had developed off-color blobs on the panel that were only visible during certain content. Technically the TV worked fine otherwise, and the issue was hard to spot if you didn't know about it. I decided to call Geek Squad out anyway and figured the guy either wouldn't be able to see it or would tell me it wasn't an issue or something. To my surprise, the guy told me he's seen the problem before, that they would try to order a new panel, and that I would probably just get a replacement TV instead. Lo and behold, they called me within a week and told me they wouldn't be able to get a new panel, and I got store credit for a new TV and a pro-rated store credit for the unused portion of my protection plan.
ht Panasonic 60" ZT60, Monitor Audio: Silver RX6, RX Centre, Radius 90HD; Martinlogan Dynamo 700, Marantz SR5006, PS3, Oppo BDP-103D
2ch Sony KDL-32W650A, Sony BDP-S1000ES, Marantz PM8004, JVC T-X3 tuner, Monitor Audio Silver RX1, REL T3, Apple TV, Peachtree Audio DAC•iT, Sennheiser HD598
lr Panasonic 50" ST60, Sony BDP-S5100, Apple TV
pc Energy CB-5, Audioengine D1, FiiO A1