I have a Samsung 55" 4k that is the best damn looking TV i've ever seen. Granted, I bought it on the spot when I noticed how beautiful it was, but that's beyond the point. DirecTV broadcasts some 4k content and I have other 4k content so I can promise you it's freaking amazing looking.
TBT, you've seen my layout...a 65 won't fit on the mantle the way my 55 will or else I would have bought that instead.