I am very pleased with my Noctua NH-D14.
6 heat pipes,120mm fan and 140mm fan.
Very quiet.
Very good reviews.
Huge.
Expensive.
Did I mention huge?
Newegg:
http://www.newegg.com/Product/Produc...82E16835608018
Reviews:
http://www.guru3d.com/article/noctua-nh-d14-review/
http://www.overclockersclub.com/reviews/noctua_nhd14/