Server 2012 R2 w/ Hyper-V role, there are several 2012 R2 and Windows 10 VMs.
All drives are in a Stablebit Drivepool with duplication.
Mellanox ConnectX-2 for 10 gigabit link directly to gaming rig via SFP+ direct attach cable.
Very nice, very clean. I use StableBits as well on one of my home servers. Eventually going to go with an actual RAID-5 card since I have no backup for the almost 16 TB of movies/TV shows.