Get as big as your budget allows.
Best bet is stay with brand names - Samsung, Sharp, Toshiba, Sony are all good bets. I'm not so crazy about Vizeo or Olivia.
Don't assume you are getting a great deal just because Circuit City is closing. Take the brand and Model number, run them through google for price comparisons. Also read any reviews at cnet, epinions, amazon you can find.
Black Friday is coming up, there will likely be some very good deals between now and Christmas. Generally the budget brands on put on sale on BF while name brands get marked down a week or two later.
for good price points as well.