I recently purchased a HDTV back in Jan. and I fall into the "brick and mortar category". I do this mostly because if something is wrong with the TV. I want to be able to take it right back to the store and get a new one. Instant gratification. I have found, though, that HH Gregg will sometimes honor an online price (though this seems dependent on the sales person rather than it being store policy).
I dispise Best Buy's (lack of) customer service. Having previously worked there in the service department (thankfully before the "geek squad")I hate hearing about the protection plan that just pads their wallets. A word of warning to the world, read the pamphlet before saying sure. If a sales rep says, "it covers everything" call him/her on it, get it in writing from them and have the store General Manager sign it. This practice is especially bad for laptop sales.
I went through Circuit City's phone option and had a reasonable experience, though i did get several calls after the fact that went something like "we noticed you do not have the extended warranty.." Also, my limited experience with CC has shown that I can generally get a good deal if you are willing to wait for the right time. I got a 46" samsung (I believe it is the 4671, but it could be the 4665... which ever has the 120hz engine feature) for 2300 that is currently listed for 3200(4671) or 2400(4665).

Or, buy one now and take advantage of Circuit City's 30 day price guarantee if it goes down in the next 30 days..
Or, if it is at Walmart, they offer a 90 day return/exchange policy and price matching