Its basically a toss up between the Tuniq Tower 120 and Thermalright Ultra-120. I'm running the latter on an E6600 @3.6 GHz with an 86cfm panaflo fan. Load temperatures vary between 58-59 in TAT. In most games, the temperatures stay well below 50. Idle temps are around 40-42 depending upon ambients. I chose the latter since the tuniq tower only accepts 25mm thickness fans which meant I couldn't put a trusty low noise, high airflow panaflo on it. The fan that comes with the Tuniq is very loud.
The Zalman 9700's performance is not in the same class. To reach a decent performance level, the zalman sounds like a jet engine. Anandtech reviewed all the heatsinks recently. You might wanna take a look at that.
C2D E6600 @3.6 (1.41V), P5B Deluxe, 2GB Cellshock 8000C4, ATI X1900XTX, 1.4TB Disk space, Dell 2005FPW, Jamo E855+NAD C320BEE+CityPulse DAC+XFI, Sennheiser HD580, Stacker 830.