Two suggestions:

About two years ago, I surprised the Mrs. with a 40+ inch for Christmas. Did my homework by going to cnet.com and they have a series of articles explaining all the tekky stuff, what to look for, etc. etc. Do a search and it will be worth the investment in time. There is a science to picking a model/size/etc. depending on where you plan to put the set, lighting, etc. etc.

When I did buy, ended up at Costco after viewing sets at Best Buy and other electronic stores. Two reasons: they had a good price, plus a 90 days no-questions-asked refund policy.

We ended up with a Panasonic 740 dp set, great buy and we loved it. Guess what the Mrs. did? On the 89th day of the purchase, while I was away, she and my son packed it up, returned it to Costco and got the same exact model but in 1080 format for $100 less - Costco did the refund/new purchase, no questions asked!