The best 'Fan Control' software?

[nambuccaheadsau]

The best?

Whatever Mac OS X system you are using. Artificial fan controls can be pretty dangerous.

 

[cynics]

Although I haven't tried SMC for a while for the last couple years TG Pro has been my favorite.

At the time it offered significantly more without any of the fluff/bloat of other non related features. The app makes it very difficult to damage anything and minimum fan speed will remain MacOS fan speed unless you specifically set otherwise and the app will make it very clear to proceed with caution (used for setting HDD temp sensor not being installed).