It seriously depends. An i7 980X at 4.8 GHz system with 24 GB of RAM, quad OCZ Vertex IIs in RAID 1+0, four GTX 480s in quad SLI at 800 MHz on shaders and core clock would destroy an Athlon II X2 250 system with 4 GB of RAM and integrated HD 4200 graphics, but then you just have to look at the cost. Besides, this question will eventually get locked... because it'll end up in a flame war.