Q: Why don't you include an optical drive?

A: Aside from installing the operating system (sometimes not even then), an optical drive is a dead and obsolete piece of technology. The PC industry has long since migrated completely to the faster, cheaper, and simpler digital distribution method. If you want an optical drive, your best course of action would be to buy a portable external USB one so there's not an extra useless part in your computer.

Q: Why don't you include a keyboard and mouse in each build?

A: Keyboards and mice are a tough thing to include, since the majority of people have one or the other already... sometimes even both. If they don't, it's still a bit too subjective to just point people to a single keyboard and mouse. There's a lot of options out there for keyboards (mechanical, rubber dome, back lights, size, noise, etc) as well as mice (laser, optical, wireless, etc).

If you are interested in mechanical keyboards, ask around! This sub and /r/MechanicalKeyboards should be able to help you out. Yes, they're freaking amazing and you will never want to type on anything else ever again.

Q: Why don't you include an Operating System?

A: There are far too many options out there when it comes to choosing and obtaining an OS. For Mac OSX fans, there's Hackintosh configurations. For Linux, you have a plethora of amazing, fast, and free distributions like Ubuntu, Elementary OS, and Steam OS. For Windows, you have Windows 7 (for those who don't want Windows 8/8.1/10), Windows 8.1, Windows 10, Windows Home Server (for hosting), etc. On top of that, obtaining Windows can be done many different ways. Some people just type in a key from another machine they already have. Some people already have it burned to a disc (which Microsoft legally distributes for free!), and some people just plain install it and ignore the activation requests.

Q: Why don't you include a monitor?

A: Consoles don't come with displays and neither should these. It would be unfair to enforce the need for a monitor when consoles don't come with them either. Besides, you can hook your PC up to your existing monitor or TV just like you could with a console. Monitors (and TVs) vary extensively, and it would be a bit unfair to try and predict what someone's needs would be. There's refresh rate (how fast it refreshes/maximum FPS it can display), there's display type (IPS for color clarity, TN for refresh rates), size (they can get pretty big), and other physical features (pivot, arm, bezel size, etc).

Q: Can you please just show me a few decent displays?

A: Yes, here's a few popular 1080P displays:

AOC E2260SWDN 60Hz 21.5in" Monitor
Asus VX248H 60Hz 24.0 60Hz" Monitor
Asus VG248QE 144Hz 24.0in" Monitor
BenQ GW2750HM 27.0 60Hz" Monitor
Q: Don't Ivy Bridge and Haswell have a slight heat problem?

A: Heat, not really. Cooling, kind of. Don't worry too much about that. It's only a problem if you intend to overclock a lot, in which case you'll probably want to de-lid your chip. Basically, Intel uses thermal paste inside their chips rather than the traditional fluxless solder to attach the heat spreaders to the silicon die. The downside is that the chips run hotter and die sooner than before. The upside is, they're super easy to de-lid and attach a cooler directly to the silicon die. Luckily for everyone, as of Devil's Canyon, Intel seems to have fixed this issue. Happy overclocking, and may your builds outlive the tyrant CEOs of the console monopolies!

Q: Why AMD in the lower builds?

A: Contrary to popular reviewers like TomsHardware and Anandtech (800x600 DX9 Ultra detail cough cough), the newest architectures are actually pretty decent. The first builds use a very new "AM1" socket and are targeted toward extremely low budgets, low-power, and compact sizes. The Athlon X4, FX-6300, and FX-8320 are a bit older, though. However, they're still very nice chips for the price: Benchmarked Socket AM1 chips, Athlon X4 [RES ignored duplicate link], FX series [RES ignored duplicate link], FX series (again) [RES ignored duplicate link].

Q: Why no i7?

A: Gaming doesn't benefit from i7s . The very reason you asked that question is the reason so many "gaming" PC manufacturers use the i7 in the first place. They use up all their budget on the i7 and then proceed to skimp on the graphics card and add a GeForce 220, resulting in an absolutely terribly-performing, plastic, and LED-encrusted machine. They know the first thing you'll be looking for is an i7 because that's what's advertised the most (and the rest of the machine suffers as a result). Don't fall for popular media, use an i5, it's one of the most solid, stable, and long-lasting chips money can buy.
For multi core optimized software, streaming and rendering in general, the higher core/thread count on the FX 83xx and i7 series does matter however.