The Sharp Aquos sets are really nice and have gotten relatively cheap compared to a few years ago. Around where I live though, they seem to have left the marketplace. With all the issues of mergers, poor financial performance, etc. some of the good brands of the past seem to have slipped into obscurity for the most part.
The LG OLEDs are very nice TVs and I enjoyed viewing them in store. Their blacks are really nice but, burn-in and screen longevity are concerns, especially for gaming and computer use.
I saw the Samsung MU8000 in person and was impressed. For a 49" TV at $700, it was a real stunner. Picture quality, with a 120HZ native panel, and overall color and vibrancy were really nice at this price point.
In the end, I got a Sony XBR-X930E. It supports Dolby Vision in addition to the other mainstream HDR formats. The other thing it had going for it was superior brightness, especially compared to the LG OLED. Light bleed through and black differences are only going to be noticed by extremely critical viewers especially looking at very challenging scenes with superior video sources currently unavailable in most homes. Overall, considering the ambient lighting conditions where I will be using it, this TV/Monitor seemed to have the best combination of features at the price point that wasn't extreme ($2K+).
The other concern for shoppers to be aware of is 'off-axis' viewing issues. Most 'LCD/LED' televisions today use VA panels. When you are 15 degrees off of dead center, picture contrast and color start to distort. OLED panels are superior in 'off-axis' viewing if that is a concern where you will use your TV. For gamers and computer users, this is less of a concern if the 'TV' part is a secondary use scenario. OLEDs in a bright room also could have issues compared to really bright VA panels since their max brightness is less resulting in possible glare image degradation relative to the better VA panels (along with panel finish (matte, semi-gloss) being a contributing factor).
All things considered, the ~$700~$1000 55" television market today is really impressive with the ~$1500~$2000 sets being very competitive with units costing significantly more. If you are shopping in store, just make sure the video sources driving the TV are of good quality or they will all look pretty much the same and you will miss what the TVs like the $700 Samsung MU8000 really offer over the cheaper options sold at the major big box stores.