I find it incredibly useful to have a trusted place where I can look up what they would recommend for some things, as I just don't get to handle nearly the amount of hardware I used to. For example, I was just contacted by one of my friends that he wants to do another build in late march to early April. Now the thing about this friend, is these builds last a looong time, as he doesn't have tons of money to burn and has 3 boys (ages 12 to 7) and he passes hardware down the chain (essentially upgrading when one of the kids wants his own PC). His current set of systems are all ones I've suggested the hardware for and helped him build, and while they get the occasional "easy" upgrade of ram, vid card, or disk, most of the system stays the same. The systems are:
i7-920 @ 3.8ghz w/ 12gb ram, GTX 670
i7-2600k @ 4.6ghz w/ 8gb ram, GTX 970
i7-6700k @ 4.8ghz w/ 16gb ram, GTX 1080
The 920 will go to the youngest, and there isn't exactly much room to upgrade it anymore, but its had one heck of a run, and will probably be around 3+ years yet. The question is, what do I build today that is going to have that kind of longevity? I haven't looked at air cooling in ages, but I don't think I can really recommend an AIO to last 10+ years. If I suggest a mammoth heatsink (d15?) what case works best with it. I'll probably recommend a Ryzen this time around, and am thinking that if its going to last 10 years, I should probably go with a 5900 - should I have him spring for an expensive motherboard to make sure it lasts?
This is where these build guides come in really handy....