I agree that a one-for-all benchmark is not feasible. For instance, I do not use my Mac pro (or any other machine for that matter) for gaming, in stead I could use a aperture-specific benchmark. 'Nuff said 'bout that though.
The main point for my comment is to ask, whether someone could compile a guide to all freely available benchmarks so that people would be able to catch the wisdoms from this thread without having to read through the entire text.
RGDS,