46" LCD/LED TV with Decent Sound and Fast Channel Changing

There seems to be a lot of discussion on here about Panasonic 47" LED TV's for around $800. I have read the reviews on the Panasonic and while people rave about the picture quality and overall value of the set, they don't like the sound from the factory speakers. Is there a 46" or 47" LCD or LED set with a sharp detailed picture and good factory sound that projects towards the front? I don't want to have to connect a receiver and speakers when watching the news, sports, comedies etc. Also, which brand has the least lag time when changing channels? I am about to replace a 17 year old 36" Toshiba CRT with still a great image and factory sound (cost $1600 back in the day and competed with the Sony Trinitron).

Go for picture and buy a top mount sound bar for $50, no receiver needed.

For that kind of size, usually most people put it in a decent sized room, meaning the speakers will likely be too weak for good audio in that room. Flat panels are so thin and made to be small that there really isn't very much room for decent speakers, so for the most part you will almost always need some additional audio device (unless you can live with dull or tinny sound).

Like Ancalagon said, if I were you, I would just buy a TV that has all the features you want, and buy a soundbar to supplement it. Although really, I prefer the sound from either a receiver or at least a 5.1 sound system.