Roughly every four years or so I do a massive overhaul of my PC. It's mostly a new build with a few drives and peripherals crossing over. In 2010 I made a rig out of most of the parts in my previous build Old Reliable. In 2014, I built The Second Wife. Now, you can find me engrossed in The Darkness.
I use my PC for...well for everything. Gaming, recording/streaming gameplay, writing professionally, budgeting, multimedia/home theater, etc. As such, it has a bunch of stuff that doesn't generally cater to certain crowds. It's too big and bulky to be a normal HTPC, it's way too powerful for what anyone needs for writing, and it has far more storage than most gamers would bother putting into a gaming machine. But it serves all of these functions for me.