Only interested in silent, low-heat, low-power PCs that run at least a 2160p and at least two 1080p on top of that - or two 2160p. or three. Yes I know that is a lot of screen. I do NOT care about fps rate as long as they can hold up 30fps, NETWORK CONNECTIVITY IS THE ONLY CONSTRAINT THAT MATTERS. One fanless silent video card is my maximum, I have no interest in Crossfire, SLI, but am happy to consider pairing AMD APUs with compatible cards so the power can be OFF to the ports while GPU is still in use - very handy for non-graphic uses of the GPU such as distributed processing/crypto/blockchain/DAG/etc.
Terrific onboard audio is useful as well because the HTPC isn't going to have room for a card, and always-on hosts need their bus off as much as possible. NOTE: Ryzen APUs still aren't competitive with add-ins. HDMI or USB audio will be used if the onboard isn't good enough, I will never put an analog card in a box.
Plus the APU (if competitive) and the other PCIe slot with a PCIe x8 SSD just for boot and cache. No interest in spinning metal inside the HTPC at all, that's what USB & Ethernet cable are for. I am no longer looking at mere dual-GbE systems now that 5GbE, 10GbE are out. I prefer not to use cards but to have these on the motherboard for power reasons (if there's no reason to turn on the bus, don't turn it on).
DDR3 systems should not overclock beyond spec but run at 2133 minimum so you can buy RAM useful in all DDR3 systems ever made in future, including 8- and 16-slot host RAMdisk boards (if anyone bothers). DDR4 systems should run slowest RAM that will still be usable 6 years from now, probably 2800 at lowest, as of end 2017 3200 appears a feasible sweet spot to avoid falling too far behind the next motherboard(s). I like to adjust this number once every two years so that I have the maximum amount of compatible RAM, but it will be reset by a big RAM purchase, i.e. I'll direct motherboard & RAM buying to remain compatible.
A10, FX-, old i5 or i7 or Xeon based systems are no longer of interest. Nothing over $1500 or with fancy cases or multiple video cards or spinning metal in the ATX case is of interest. I will look at ATX & mATX & ITX, but not EATX.
New i5, i7, i9, Ryzen AM4 & sTR4 Threadripper builds, plus a few random junk builds based on parts that cost less than US$300 and can be found used, are my focus here.
I build only about 1/4 of my parts lists, because I only order when a machine dies off or a function has to be split between two. Some of the parts listed were actually considered for use in one build and ended up in another, used because I got them cheap or free or in salvage or trade. Thus the prices listed aren't necessarily what I paid, and I'm not recommending ANY vendor based on inclusion of that part. In some cases I cannot find the parts I have and am forced to find a close equivalent in function to make PCP happy. So I am not recommending the parts either, unless I have said in description specifically that I do.