AnandTech - Bench - CPU
If money is no object, Intel. The top two are 6 core Sandy Bridge E processors. (You could bump it up further with an 8 core Xeon, but that would limit your motherboard choices.) An Ivy Bridge based machine (I7-3770k) isn't far behind, and probably gives a significantly better price/performance ratio.
For the GPUs, the choice is less clear. The nVidia GTX680 and AMD Radeon HD 7970 cards are the best single-processor cards available at the moment. The nVidia card uses less electric power than the 7970 (mainly relevant to the PC's cooling burden), and I tend to prefer nVidia's drivers, but both are good.
If you need professional OpenGL, you'd have to look at nVidia's Quadro series or AMD's FireGL. The top-end cards in those series are much more expensive than consumer cards.