If you do buy online, make sure you read what the sites dead pixel return policy is. Many don't let you return the TV unless there are a certian number dead, such as a minimum of 8 dead pixels from Newegg.com. That's a BS policy in my mind. If I'm spending that much on something, I expect it to work perfect out of the box. A single dead pixel is not perfect to me, which is why I prefer big-box stores for LCD's.
Granted, dead pixels are much less of a problem now days, but they are still out there.