Pretty much a general purpose rig to replace an OEM Dell machine I had for a few years. Spent a good six months watching for deals/rebates and eventually bought parts from TigerDirect, Newegg, Amazon, and Microcenter. Rebates and patience go a long way to saving a few bucks here and there. A few other components like the HDD, CD/DVD drive, and second monitor were salvaged from the Dell PC. The Cooler Master HAF case (replaced Lian Li case), Asus monitor, Corsair K70 keyboard (replaced Logitech K360) and Corsair PSU (replaced Cougar PSU) were upgrades bought over the course of the next few years.
I'm using the build for a variety of purposes: a good bit of programming, some VMs (hence the 16GB RAM), a little gaming (mostly Starcraft and other RTS), some video editing, Bitcoin mining (not really profitable), and schoolwork.
Recently moved from a smaller Lian Li case to the HAF X and it's been great even without some of the awesome features that the newest cases sport. The Corsair HX750 has some beautiful aesthetics, especially the black sleeved cables, and feels pretty solid.
And yes, I love the red LED lighting (NZXT HUE is great) and when I upgrade processors I'll buy an ROG motherboard to match :) The Corsair K70 Cherry MX Blue with Red LEDs matches it perfectly!
No problems with the Asus monitor except for one bright pixel on the far right edge (doesn't bother me much). The Dell monitor is from an old computer.
I've only had a few problems with the parts: had to RMA a MSI 460 (experience was fairly painless) and I seriously messed up the Sentry's wiring and burned some of the plastic cabling when I was transferring to the HAF X. Fortunately, I was able to figure it out and fix it up (none of this was NZXT's fault). I've also had a little trouble with the RAM and had to RMA a module once (also relatively painless process).