Avoid Vizio and all other "lesser" brands - you will save a LOT of money in the long run by buying an established brand. Vizio is not made by Sony.
My Samsung 40" 1080p LCD I bought just over 2 yrs ago is still rock solid, and has a beautiful picture. One thing I like about Samsung is that they include picture adjustments that are very advanced and other brands only have them in special service menus where only a technician can access them.
I avoided Toshiba back then due to the "green monster" problem - they might have solved it since then. Sony also had a bunch of stuff going on, and Samsung was the one connected with least problems, and I think I made a wise decision. With the million adjustments it offers, and a few articles from AVS.com, I was able to calibrate/set up the TV to near professional levels, and couldn't be happier. It also has the great "any net" function, where any reputable blu ray or dvd player by major brands are detected - when I press play on the Panasonic blu ray player, the TV automatically turns on switches to the correct HDMI input - love it.