Not really a fan of Zalman HSF because it is not very easy to replace the fan should it go bad.
If you have a tall / wide enough case I would use either the Scythe Ninja+ or the Tuniq Tower. Scythe Ninja+Tuniq Tower
I have both and they are excellent HSF. The Scythe Ninja is quiet by default and the Tuniq Tower comes with a fan controller to make it quiet.