I needed something better than a 8 year old Thinkpad T60 to develop in Unity, edit video, animate in Flash, play anything aside from Microsoft solitaire, and a whole bunch of other stuff that was taking way longer to do stuff with than it should have. So I decided to build a PC. I started out with Evan Austin's $400 build, but decided it wasn't going to be adequate for anything, so I embarked on a quest to create the greatest price to performance build in history, carefully looking at all the options for every part in the build. I eventually saved up half of the money for my PC build and my parents and grandparents put in the rest resulting in the best Christmas present ever. It took three days to build.
CPU: The Intel Core i5-4690k is basically the best CPU for anything like video editing, while staying under $200. Plus I got mine for $185, which was quite the savings of $25.
CPU Cooler: The stock Intel fan, which despite a lot of circlejerking by some people, isn't even audible and is the best option as long as you're not overclocking IMO.
Motherboard: It took a while to find the perfect motherboard and the MSI Z97-GD65 is not only the best motherboard functionally, but also has benefit of epic looking dragons on it which instantly makes it the best.
Memory: Best RAM for the price and I can still upgrade to 16GB if I ever need to.
Storage: While the Kingston SSDs may have been cheaper, they probably wouldn't have been worth sacrificing the reliability of a Samsung SSD. With 120GB, it's bigger than my old laptop's hard drive and definitely has enough room for your operating system and stuff and it boots in seconds. The WD Blue is pretty much the go-to choice for literally anyone building a PC, there is no better hard drive.
Video Card: MSI's Radeon R9 280 card is definitely has the best price to performance for a video card. It's considerably better than the 270x, while still being under $200.
Case: The SPEC-03 is the best case not only of the Corsair SPEC series, but also the best looking, best at cooling, and everything else. A cool thing about it is it's built in SSD racks, which are nice.
Optical Drive: IT WAS THE CHEAPEST ONE AND IT'S GREAT.
Operating System: I got Windows 8.1 since it's the newest Windows OS and i'll eventually be able to upgrade to Windows 10, once that comes out.
MOWSE: THE RAZER DEATHADDER. I actaully got this in the Gamespot E3 swagbag giveaway that I won which is amazing. There was also a Razor hoodie which is beautiful and i'm currently wearing while typing this right now.
Monitor: ViewSonic VX2252MH. Best monitor.
Keyboard: An old Dell USB keyboard. It's pretty swag.