I have a Vizio 32" in my bedroom and a Samsung 40" in the living room... the Vizio's picture doesn't even compare to the Samsung, but it's a GREAT budget TV, considering the Samsung ran about triple the cost. I'd go for Vizio.
Also, something to note, the Vizio is considerably older (coming up on two years...), so there is the real possibility that they have done a fair amount of catching up since then.
I just love my ToC Samsung //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif