There's a lot of people in this thread that really want at least a 60" set.
My best advice based on long time experience is.. absolutely NEVER buy a smaller set than what you're really looking for.. regardless of price. There's no such thing as a tv being "too big", but there's definitely problems when your set is too small for your area. That's a real problem which will you give you serious buyer's remorse.
55" sets are just not very big anymore. They're more like an entry-level size, just like 40" sets used to be about 4-5 years ago.
55" just isn't big enough as a centerpiece set for a living room or theater room. Most people now realize they need at least 65" or 70" sets for those type of rooms. And of course there's now a lot of demand for sets between 80" and 100".