Samsung HU8500 with the SEK-3500 one connect box.
Initially it had serious issues with stutter on broadcast material but over time firmware updates seemed to have improved things along with the improved hardware in the sek-3500 evolution kit.
I've never found Samsung's upscaling extraordinary TBH so maybe different tastes for different people. And I don't see it far away or really anything much different to LGs current offerings.
The best I've seen is Sony and Panasonic with Panasonic having the edge.
Near black is just an issue for OLEDs. Its the achilles heel and the weakness of the technology. Part of the issue is uniformity, part of the issue is that lower bitrate sources lack a lot of data in the darker scenes (its why the GOT broadcast scenes fall apart but the Blu Rays are pristine in darker scenes). On a TV which is crapper in contrast and ability to deal with these darker scenes like an LCD panel, these scenes generally don't stick out like a sore thumb because the human eye becomes accustomed to the poor handling of black and picture quality. So although the dark scenes look crap on them, they're unfiorm.
I had this phenomenon with my projectors. Its not that their near-black handling is especially good, its that they're basically just not ever properly at the colour black, so everythings in easy mode for them. Simiarly for the Samsung TV in my upstairs bedroom.. near black handling is okay on the TV... but thats only because it basically can't even begin to approach what an OLED can try to interpret from the data presented to it from a picture. Its easy to do near black handling when you're not having to actually do the colour black but only ever dark grey.
Add that to the inherent tech limitation of OLED which should be mild banding on 5% grey slide (not the utter crap that 3 of us 77'' OLED users have been given).. and thats kind of part of the answer.
Now this banding is the same tech flaw as an LCD has for light bleed, DSE, LCD banding.. so again, although LG should QA and not have terrible banding on their TVs, its not something they can completely eliminate (and trust me.. I'm one of 3 people on this thread who should be crying from the rooftops about banding but I like to stay fair).
Can LG do more? Sure. But I think everyone can do more with these sources. I think Sony and Panasonic lead the pack but honestly, NO ONE is going to advertise these TVs with 480/720p content and even TV reviewers seldom spend more than 60 seconds talking about it.. because the findings are consistent with thats happened ever since 4K was first introduced.
Not trying to be a knob on the thread.. but a lot of the issues people are encountering have pretty clear explanations, but at the same time some of these issues don't have good enough explanations (the banding, the lack of DTS, the floating blacks in dolby vision mode).