The TV, like the computer mouse or the inkjet printer, has run up against a kind of creative asymptote. There was once a period when it made sense to upgrade your TV every few years, because the technology was improving by leaps and bounds. New models had HD, or USB ports, or just obviously better screen quality. But now, they’ve become something close to a commodity. You can get a 50-inch, high-def LED flat screen from a major manufacturer for well under $1,000. (Here’s one for $648.) That’s more than enough for most people. And unless you’re a real screen geek, you probably won’t notice all that much difference in a new model that costs six or eight times as much.
More to the point, TV manufacturers don’t matter. Remember when it was important to buy a Sony? Now, you can get just as good a TV for really cheap from an off-brand manufacturer like Seiku or Westinghouse, etc.
TVs have reached the same point computers have: a decent one will last five years or more so there’s no need to upgrade unless you absolutely need to.