I don't know which is best but I'll give you the lowdown on my Ninja.
Using the Ninja on a non-overclocked (currently!

) E6300. 120mm Scythe fan (included) with FanMate2 controller running fan at 850 rpm gives me an idle temperature of 36 to 39C and a full load temperature of 44 to 46C (running two instances of Super Pi). I cannot hear the CPU fan through the case. If I stop the fan, there is no difference in case noise as other components are louder. I used Artic Silver 3 (haven't bought new stuff yet).
Also, case fans are running on the Antec NeoPower 480 so they run very slow (120mm fans) and super quiet but don't pull lots of air so more airflow would give me even lower numbers.
Other components in the case include 2GB of PC6400 OCZ Gold XTC and XFX 7600GT XXX edition (using Arctic Cooling Silencer NV 6 version 2). Also have 320GB Seagate 7200.10 series drive. Using ThermalTake Mambo case with front and rear 120mm thermally controlled fans with all side vents covered in noise reducing foam.
One nice side effect (IMO) is some of the air that blows through the Ninja is directed down toward my video card. I might get a passive cooler and see if the Ninja would cool it enough with the air blowing to run stable.
