I picked all my parts and paid the shop to assemble the machine for me. I installed Vista 64. I added another 2x 2GB RAM to bring my total to 8GB. I've had zero problems with Vista. I never crash running 5x WoW for many many hours. I almost never shutdown/restart the PC, only put it into sleep mode when I am not using it.

Maybe I was just very lucky with the components I picked. I would buy a Gigabyte MB again in a heartbeat, been extremely stable for me thusfar but I also haven't overclocked anything.