Hand-assembled desktop:
Case: Corsair Obsidian 650D
PSU: Corsair Professional Series Gold 1200W
Mobo: ASUS P8Z77-V
CPU: Core i7 3770K
RAM: 32 GiB DDR3-1600 (Komputerbay)
Storage: 3 x 4 TiB HGST 7200rpm 3.5" + 1 x Seagate Barracuda 4 TiB 7200rpm consumer HDDs (in hardware RAID10)
RAID controller: Adaptec 6405E
GPU1: Sapphire Radeon HD7970 (reference design with impeller)
GPU2 (in CrossFireX): XFX Radeon R9 280X (with three large 'standard' fans and clocked at GHz Edition speeds)
Soundcard: Creative SoundBlaster Z
Accessories:
Headphones: Steelseries H Wireless connected via bidirectional Optical (Mini-TOSLink) to the SoundBlaster Z
Display: Panasonic VIERA TC-L32DT30 HDTV (1080p60)
Keyboard: Das Keyboard Model S Professional
Mouse: Steelseries Sensei
Mat: Razer Vespula
The story:
Ordered the HD7970 in February 2012 and stuck it in my old box for a few months.
Ordered the CPU, Mobo, case, PSU, two HDDs (one of them has since died), and RAM in April 2012 and built new box by adding GPU. Handed down my old box to a family member along with my older GPU.
Ordered the Adaptec RAID controller a couple days after getting the box together and realizing I didn't like software RAID.
Ordered the SoundBlaster Z in February 2014 in preparation for the arrival of the Steelseries H Wireless (pre-order) in March 2014.
Ordered two HGST disks in March 2014 and combined them with the existing two Seagate disks to make a RAID10 array.
Ordered the R9 280X in June 2014 after realizing how cheap it was and that I could Crossfire it with my existing card because it's the same chipset.
One of the Seagate disks failed badly in August 2014, but I didn't lose the RAID array because the other three disks were fine. I overnighted a new HGST disk (same make and model as the other two) to replace it. At present, I have one of the original Seagate and three HGST disks still in the RAID array.
The configuration has been static since then.
Presently I estimate that this system has gone through about 75-80% of its service life *with me*. Since I'm a gamer, coder, virtual machine runner, and general all-around resource hog, I'll be looking to upgrade when Skylake mainstream processors land. I'll probably get a Skylake "K" (unlocked) i7. Of course, this system is perfectly serviceable for lighter duty gaming and web browsing, so I expect it will become the upgrade for the same family member who is using my old system today (though with a few retrofits due to some component failure).
The internals of the case are an absolute mess; a tangle of poorly organized cables. The only thing that keeps it even slightly manageable is the modular PSU; I removed (or never plugged in) all the molex connectors I'll never need.
One of the big limitations I've come up against with this system is the limit of the number of PCIe lanes and slots. I'll definitely consider this more heavily when I buy my next system, but I understand that Skylake mainstream is going to be expanding the number of lanes anyway.
Right now, this system can play 2014-and-earlier AAA games at maximum detail (or very near to it; some settings are just so poorly optimized that they're not usable), even on a single GPU. With CrossFireX I just get more consistent framerates (AMD's Frame Pacing feature is a lifesaver).
I'm starting to feel that it is experiencing significant slowdowns, even in CrossFireX, on the latest AAA titles. Dragon Age Inquisition and The Witcher 3 are giving me a lot of trouble. I am not sure if it's due to their poor driver maintenance, bad optimization, or Nvidia-favoring algorithms. I can probably deal with this performance deficit for the remainder of this year, but I will definitely want to upgrade in time for Star Citizen.