This is a high end gaming and development machine. I put about 30-40 hours of research into building this thing over about 2 weeks. I'll just go part by part with a short blurb on why I chose it.
CPU: New architecture, new socket, MOAR COARS. Roslyn and VS2015 come out soon, so I'm going to want this for the multi-threaded compilation advantages.
CPU Cooler: Most extreme aircooler I could find. Didn't want to deal w/ watercooling. Support for the 2011-v3 socket out of the box.
Thermal Compound: Made of micronized diamond, the most thermally conductive material known to man. @8 dollars this was a no-brainer even though it's kind of "overkill".
MOBO: Good reviews minus some DOA's/Infant mortality. 8 slots for ram (want 8x4gb eventually). Wireless support. Tons of USB/SATA ports. 3x-SLI capable. ASUS so you know it's solid.
Memory: Have had good experiences with G.Skill's Ripjaws series in the past. Went with entry level for now, will upgrade to higher clock later maybe.
Storage: Big SSD for OS/Games/Development. Big HDD for media and dev archive/artifacts location. Have had awesome experiences w/ both Samsung and WD in the past.
Video Card: Highest clocked dual-fan GTX 980. Best overall performance of GFX cards out today, excluding certain Titans that are far more expensive, and especially considering power-draw. I trust EVGA the most out of all the GFX Manufacturers (MSI is great too though).
Case: Put a LOT of research into this one. Decided on it because of lots of space, tons of fans, amazing dual compartment setup for HDD/PSU and cabling, great cable management features, high airflow capability, and a nice aesthetic. Loved the build-in and supplied velcro straps and well placed rubber grommets for cables everywhere. Easily removable, and ubiquitous dust filters were probably the deciding factor on this.
Power Supply: Seasonic is a trusted high-end manufacturer of Power Supplies for the likes of Corsair and Antec, with a great reputation. Wanted fully modular and with enough headroom for another 2 GTX980s and a few more hard drives when build is completely finished in a couple of months.
OS: Games. C# Developer. 'Nuff said.
Monitor: Was looking for a big 120HZ monitor. Read about this thing and G-Sync and figured I'd pay the premium to eliminate screen-tearing, even at low rez. Works quite nicely. It was constantly sold out, so I had to import it from amazon.co.uk and get a US wall adapter for 5 bucks from Monoprice.
Keyboard: Cherry Mx Browns? Check. Macros? Check. Absurdly excessive programmable 24-bit color LED-implanted Keys? Double freakin check!
Mouse: I like Logitec mice, there's plenty of buttons, absurd DPI, and macro capabilities. After using it, it's quite comfortable and the blue G-LED has a cool adjustable breathing feature.
In retrospect, I'm happy. My only gripe is a feature and something I wouldn't change - this thing is ridiculously heavy and was a giant pain to carry up 3 flights of stairs! Another centimeter or 2 of clearance on the cable management side for the panel would have been nice too, but I managed fine.
EDIT: I haven't started tuning anything yet, so it's all stock. If I get time I'll come back with some stats when I have them.
Started adding some stats. All temps are with full cooling enabled.