Stock:
Intel: more expensive, more power efficient (for the same performance)
AMD:
Cost less (for the same performance),similar power consumption at idle,less power efficient although not significant in most cases unless PC is at 100% 24/7.
Overclocking:
Intel: Good overclockers but
YMMV, high speeds attainable with acceptable increases in heat and power,
very hard to get budget overclocking motherboards for under £65 now.
AMD: Mediocre overclockers, lower speeds attainable,
higher power & heat output.