Simply put - intel is better clock for clock, and their manufacturing process for their CPUs is second to none. AMDs CPUs are fine for APU designs, small file servers, low power.
On the GPU side, its always a battle, and more based on your own experience in the end. Ive had MANY Nvidia GPUs dating back to the 7600 series, along with ATi/AMD dating back to the 5400 series. Personally, Ive always found Nvidia's cards to be the better card in terms of QC. Rarely have I needed RMA for any of them (even the real hot gtx 295 still hums). Most I have had happen, was a lightening strike that ended a gtx 580.
I wish I could say the same for AMD/ATi, currently I have a 7950 that is less than 6 months old(purchased in May). Already I am on RMA #3. The second RMA was a NEW card mind you. Already, I need to send it back for service. due its display outputs just dropping out and no longer working. I dont use my GPUs for gaming,but for CAD/CAM and some mild video editing; Exploiting the OpenGL, CUDA, OpenCL languages, and we NEVER overclock our GPU's. Granted, Ive better luck with the 6700 series, none of them are still working as of now.
(To those ready to jump on my case)Yes, they are properly powered, cooled, etc.. Our machines sit in a dedicated server room, kept at 65F at all times. Using nothing but gold to platinum rated PSU's with 30%(10-15% being average) capacitor degrade equated. Our PSU's NEVER see past 60% load to them.
This isnt me saying AMD sucks, this is nothing more than my own experiences with both companies. To me, it comes as no surprise. OEMs aside of course.