Personally for your use case of gaming, movies and youtube etc...Intel have the edge in raw horse power, especially on the gaming side...2 problems, one the 8700K pricing has gone through the roof due to 14nm production shortages and at $400 now it is very hard to recommend, even from a 8700K user like me who absolutely loves the performance of this CPU..it is stellar...The 8700K is perfect for your use case in every way...
Secondly and probably more important is the imminent release of the 9600K, 9700K and 9900K (9900K = the 8 core 16 thread 5GHz stock monster with soldered IHS so overclocks over 5GHz could be the norm now) soon to launch in October, so anytime in the next couple of weeks. I would wait and see how these perform and what the pricing is...
Finally, you cannot go wrong with Ryzen either..The 2700X is a more than competent CPU that will handle pretty much everything you throw it's way though you get more out of it on the productivity side and of course it is cheaper.
If money is no issue, I would wait a couple of weeks on the 9900K and then make a decision...