In most cases, retail experts say, the slightly older TV models are perfectly fine. Most of what people will buy this season will get them a lot of mileage. For those looking to pick up a new set for the big game. In previous years, some of the best prices were on 42" screens, but as overall prices drop, that sale competition has shifted to 55" sets. The average price of 60" plasmas fell 37% in 2011. The best sales right now are coming in around $800, nearly $200 cheaper than comparable LCD sets.

Sports fans in particular will want to watch out for slower refresh ratings, which means the set doesn't adjust as well to fast motion. And 720p resolution, although less expensive, won't give as good a picture as the more standard 1080p.

There's an undeniable appeal of a set capable of playing 3D movies or connecting to the web. But such sets still sell for premiums of roughly $200. For instance, 3D television content is still limited -- the Super Bowl won't be broadcast in it -- and a web connection can be achieved through devices shoppers may already own, such as a Blu-ray player, video game console or web TV box. Shoppers will find Internet connectivity or 3D a better deal if they were already in the market for a top-of-the-line set. Even then, they should proceed carefully: Manufacturers have yet to settle on a standard 3D technology, so there's the risk that a set could use one that will be obsolete.