Form factor seems to be a key buzzword this day and age, with many people opting for small systems that can just do what they want. This is also a common argument people use during the console vs PC debate. A common statement I've heard is that you can't build a PC for a similar price to the consoles. Well, I'm gonna crush that argument today, and put together an Affordable ITX build that will play tons of games at better settings than the consoles for a similar price. As usual, all prices will be USD from Amazon.com unless otherwise noted. Let's get started.
CPU: Intel Core i3-4150
For a small form factor PC, you want something that won't produce a lot of heat and doesn't require a lot of power. That's where Intel's i3 line comes in. A dual core processor with hyperthreading, this chip will hold its own against some of the higher core processors in gaming. It isn't overclockable, but you don't need to overclock a processor in mini-ITX anyway, since you want to keep everything at a low number. Heat, voltages, etc should be minimal, and only use what you need. This processor will do fine in gaming and is perfectly capable of media streaming and H.264 encoding and decoding. Everything a mini-ITX computer needs.
Motherboard: ECS H81H3-I
I know, ECS isn't really well known, but they do make surprisingly good stuff. Nothing too fancy, just the bare minimum, but you don't need much else. It comes with a USB 3.0 header, 4 USB ports in the back, plenty of SATA ports, and a full size PCI-e x16 port for your GPU. It'll be plenty for this computer, and will allow you to do a few upgrades if you need.
RAM: PNY XLR8 8GB
We'll go with PNY RAM again, since they make good, affordable stuff. Heatspreader, Cas latency of 9, 1600Mhz, it's all good. And since it's only a single DIMM, you can upgrade to 16GB later and add a lot of performance when you need it.
SSD: PNY Optima 240GB
PNY comes in again for the SSD. We're going with a rather high capacity SSD since it's a small form factor machine. We don't want a lot of moving, loud parts, and the SSD will also allow more air to circulate in the case since it is much smaller. They also produce less heat and don't take up as much power. 240GB might be a little low, though, so if you have a NAS or an external hard drive, it's definitely recommended when you need it.
GPU: Gigabyte GTX 960
For the GPU, we'll keep the temps and power down with a GTX 960. The Gigabyte variant uses a smaller Windforce cooler with dual fans instead of triple, but that won't be a major problem for this card. It sips power with it's 120W TDP, and only requires a single 6-pin power adapter, meaning you won't need a huge power supply to run it. The 960 is more than capable of running games at high settings and 1080p, even though many critics don't like the 128-bit bus for the VRAM. While it would be nice to get 3GB of VRAM, 2GB is fine for 1080p gaming, and this chip uses some special tricks to utilize it to the full potential.
Case: Cooler Master Elite 130
This is my favourite mini-ITX case, even more than the Fractal Node 304. Personal biases aside, this case is really good. It comes with a front intake fan to help keep everything cool, allows for a full size ATX power supply, looks pretty cool, is tiny, and even can fit the massive Radeon HD 7990 card. It's really crazy how such a small case can fit all this. It could be improved with dust filters on the side vents, but it is still a really good, affordable mITX case. I've seen it go for $30 some times, too.
PSU: Corsair CX430M
We'll go with a modular PSU to keep everything nice and neat. You'll probably only need the PCI-e and a single SATA cable for this setup, so this will be fine. 430W seems like a small amount, but it's not when you take into account that the entire system will only use about 240W under a heavy load. That's crazy, so the 430W PSU is a great value for this setup.
So, what's the total price of all this? Before rebates, it's about $615USD on PCPartPicker. After rebates, it will cost only $560USD. So you can build an Affordable ITX computer for not much more than the consoles and it will beat them in pretty much every game you can throw at it.