I have a 32" Westinghouse LCD. It's an older model, but is awesome. Had it for about 2.5 years and its a rocking TV. Would definitely buy Westinghouse again.
I remember reading somewhere that at more than a couple of feet away from a screen your eyes can't see the enhanced resolution from 720p to 1080p. But that being said, I agree that 1080p will be able to handle everything so might as well buy it. From a personal experience I have a 720p TV and can't tell a difference between that and 1080p on my friends TV. Both look amazing.
I think where you put the TV is also a factor. If you're putting it a brightly lit room, then LCD is better than plasma. That could be a factor for some who's TV is in a room with a lot of light.Size: 40" or small buy an LCD, 50" + buy a plasma
And I agree about the Costco, I know they have a lifetime return policy. You can return it for whatever reason.