Q745A576 has probably the best results I've seen anywhere in terms of hitting high stable clocks with very little voltage.

4ghz - 1.675vcore - SUperPi 1m
4ghz - 1.20vcore - Prime95
4.25ghz - 1.28cvore Prims, Orthos, OCCT stable
4.6ghz - 1.41vcore SuperPi 1m sub 10sec.

I dunno, has anyone seen better results?