Short answer, the best PC is one you build yourself - or have built for you, if you don’t find high-stakes legos fun. A box PC will save you work in assembly time, but to make sure you’re getting what you need you have to know what you want anyway, so you might as well have it built rather than try to find a best fit.
If you’re doing video and photo editing, the two most important parts are going to be your RAM and your Processors. You may want to have a dedicated GPU, but a beefy enough CPU should function fine.
To briefly explain, the Processor is “processing” everything you do - it’s running the equations and the math that makes the programs do what they do. If you’re doing any filters or rendering, you want as big a processor as you can justify spending on. a GPU is a Graphics Processing Unit (as opposed to Central Processing Unit) and is dedicated to processing imaging and sound, which is why they’re often packaged with G A M E R styles. The RAM is “random access memory” and is basically where your computer puts all your history - when you use cut/paste or undo, it’s pulling that information from your RAM. That’s not the only things that it uses it for, but those are the ones that will concern you. And if you’re cutting and pasting parts of videos in editing software…yeah, you want a ton of that. Good news is RAM is one of the cheapest parts of a PC.
After those two are taken care of, most everything else is just accommodating those two pieces and making sure they can do what they need to do.
And as far as OS goes? I prefer Windows because it’s what I grew up on, but having used both, honestly, it’s just a matter of what you’re used to. So many things are “The Same, But Slightly To The Left” between the two (I’m looking at you, Command/Control buttons).
In short, if you’re buying a box off a shelf, Macs are never bad - but if you take the time to build it out, you can get a better PC.