My current computer was built in Dec 2012, with some updates since (i.e. video card). I'm usually on a 3 year refresh rate. I'm thinking that I'll be building my next one when Skylake comes out.
I use mine for photo editing, video editing, gaming, GNS3 (Network simulation), etc. It was built primarily for gaming with the thought that anything else thrown at it would work just fine. The weak point in my system are the displays, its past time for new monitors. For gaming I use my 52" Samsung Plasma but I plan on moving to a 3 monitor setup, which is why I have the 970.
System:
ASUS P8Z77-V PRO LGA 1155 Intel Z77 HDMI SATA 6Gb/s USB 3.0 ATX Intel Motherboard
Intel Core i7-3770K Quad-Core Processor 3.5 GHz 8 MB Cache LGA 1155
G.SKILL Ripjaws Z Series 16GB (4 x 4GB) 240-Pin DDR3 2133 (PC3 17000)
MSI GTX 970 GAMING 4G GeForce GTX 970 4GB
Sapphire Radeon HD 7950 3GB DDR5 HDMI / DVI-I
Creative Sound Blaster Audigy2 ZS Platinum 7.1 Channels 24-bit 192KHz PCI
2x Samsung 840 Series 250GB SSD (System, Programs)
5x Seagate 2TB 7200RPM SATA III drives (single drives for data, no RAID)
2x SATA drive bay with 2.5" and 3.5" hot swap SATA slots
2x BH14NS40 14x Blu-ray Disc Rewriter
CORSAIR HX Series HX850 850W ATX12V Power Supply
Antec P280 Black ATX Mid Tower Computer Case
Displays:
Dell 2405FPW 24" 16:10 monitor
Acer 24" 16:9 monitor