the big brands, but often they have slightly different models (e.g. a just for Sam's Club model).
I am wary of Best Buy because they really rip you off sometimes. I assumed that I was buying TVs at Sam's club/Costco because it is a good deal, but it might just be habit at this point.
Last TV I shopped for the main thing I wanted was minimal lag and I found something just fine at Sam's.