Highest level Intel CPU overclocked with a couple of GTX 980s running on the Asus Rampage V motherboard 2011 socket with Corsair Dominator Platinum DDR4 populating every single slot. Hook up an AX1200i for the power and sit it in a custom carbon fibre case. Custom watercooling with multiple radiators will keep it cool and while we're at it let's have a full size air conditioning unit pumping icy cold air directly through those radiators using some ducts.
Although building this computer would be simply ridiculous, it was certainly fun running around my favourite website for the most expensive performance parts.
EDIT: Load it was Samsung 850 Pro SSDs in 1TB using RAID for storage.