Aha! Finally, some stated requirements.
Ok, I have no idea how long this post is gonna go, or whether I'll still be awake by the time it's done.
The reason people (myself included) were throwing heavy hardware at you is that your choice of CPU and motherboard are the ones that a guy at home trying to do 3D fluid simulation or video editing might choose. You don't put 6 cores/12 threads of server-grade silicon into your box unless you plan on mating them with a lot of other high-end hardware for churning through lots of transcoding, 3D models, scientific simulation, or the like.
These days, the majority of games run just fine on only 2 cores, which means any of a number of 4-core processors will easily be able to meet your needs for many years to come. Also they are much cheaper. Video decoding doesn't even need 4 cores, it can easily get by with only two, but I'd still recommend at least 4 for future-proofing. The only question is whether to get an i7 model that supports "hyper threading" (HT) or an i5 model that does not, and the answer to that question is a) Can you afford it (i7 processors tend to cost a bit more than i5) and b) do you see yourself doing any transcoding in the future? If so, then get an i7, because the ability to process an extra 4 threads will really save you time (about 30-40%) when converting between video formats.
If you are wondering why I am not recommending AMD CPUs, that's because they are not competitive on the high end. That might change early next year with their Zen chips, but those aren't here right now.
On to the motherboard. It used to be that the northbridge chip (usually the biggest one on there) ruled just about everything, but so many things have moved to the CPU now that it's not as busy as it once was. This is what I was getting at with "PCIe lanes" in my first CPU recommendation. See, even if the board has 50 PCIe lanes or some other ridiculous number traced onto it, all those lanes have to connect to stuff at
both ends, so if your CPU doesn't have enough connections to actually
use all those lanes, a bunch of them will just stay dark and unused. When you remember that one graphics card can command 16 all by itself (that's what the "x16" stands for in "PCIe x16"), you can see how much of a difference there would be between your CPU having 28 v. 40. Nowadays, the northbridge chip mainly does a sort of "plumbing" job to bind your CPU and RAM to each other and to the rest of the board, but it still has some other functions, like running your SATA or M.2 ports or the like. Features vary depending on which northbridge (or "PCH" (Platform Control Hub) as Intel likes to call them) is installed on your board AND for this reason your choice of motherboard is probably THE MOST IMPORTANT choice you make when deciding a build, as it is the part that joins all the other components together AND it dictates so many of your other choices.
So here's my advice. Decide which processor "family" you want to go with first based on the performance/price you're looking for, and then decide which motherboard to slide under it based on what you're going to be doing with that processor. For instance, if you won't be using dual graphics cards, then you don't need a full-sized motherboard with extra slots. If you are going to want 6 hard drives in your system to hold all your movies, then get something that has 8 SATA ports to plug them all into.
If you are looking for top end "consumer" processors, right now that means your choice is between these three (oldest to newest): i7-4790k (Haswell), i7-5775c (Broadwell), or i7-6700k (Skylake). All of these run about $330 right now. Their i5-equivalents are the i5-4690k (Haswell), i5-5675c (Broadwell), or i5-6600k (Skylake). The i5's run about $50-$75 cheaper than their i7 counterparts. If you want to see how the i7 variants compare against one another, you can
click here for one of the few reviews out there I know of that includes benchmarks of all three (among others). You'll probably be surprised at how closely they perform (at stock speeds, no overclocking applied). If you want to compare the i7 features side-by-side, you can
click here to get the skinny directly from Intel (or
click here for the i5 comparison). I know you won't necessarily know what all the rows mean (even I don't know what
all of 'em mean), but you can see things like operating temperature, maximum resolution using built-in video (
All of 'em can do 4k UHDTV @60Hz with just the built-in GPU and no graphics card!), maximum amount of RAM supported, whether or not they support integrated VGA out, or other things you might be interested in knowing (or asking). You might even find the integrated video is good enough for what little gaming you do, and so decide to skip buying a GPU completely for a couple years.
It's quite do-able.
This might be more than you wanted, it might be less, there might even be an inaccuracy or two. But lemme know if it helps.
--Patrick