Battlefield 3 campaign.
I'm doing to Paris level and my jaw has been on the floor the whole time. The game runs REALLY well compared to the beta and the Crossfire scaling is nearly perfect. I'm playing at a mix of high and ultra settings with 4xAA.
Core i7 5820K hexa-core @ 4.4 GHz | 16 GBs 2400 MHz DDR4 | Dual MSI GTX 970s | Dual 128 GB SSDs