Zalman ZM-F3 - The shocker of the whole group. Really, it came out of left-field. No fluke here either, Cathar got nearly identical results. No extraneous noise, magic-scaling above ~1600RPM, does well on a
radiator, a mere $10 and available nearly everywhere and just overall great performance. A gem of a fan in many respects. It is a sleeve bearing though, it's only detractor.