I can’t agree with the Nanocell recommendation, nor do any of the reputable TV reviewing sources (ratings, hdtvtest, etc.). @Superman2x7, if you’re looking at an LED, the Samsung Q80 or above are your best bets, assuming you’re trying to get the best of the technology. If you’re going OLED, than the CX is the best option; just remember there’s a large price delta between the sets.
I’m not going to go into the nitty gritty of which is better because there are genuine use cases and environments where one excels over the other. Personally, in my situation, I prefer the newer QLEDs and in the incoming MiniLEDs for a number of reasons, after owning an OLED for four months. I have found the lack of brightness with the OLED to be greatly disappointing when compared to even the now-five-year-old KS8000, which results in relatively lackluster HDR highlights and atrocious performance in my living room during the day time (even with curtains). As someone who uses my sets a lot, I worry about the longevity as OLED will naturally breakdown over time and with more heat/use, that will occur quicker; full disclosure, I purchased the set at a price too good to pass by, but the fact that I’m already looking for my next set isn’t a good sign.
Also, keep in mind that the new sets are going to start launching next month, so some of the recommendations will be likely to change. Finally, if you’re looking for cheaper options, I can recommend several as well.