I'm currently running a Lian Li G70 with a PA120.3 in the roof and a Lian Li S80B with a PA120.3 in the roof.
The S80B is silent. Absolutely not a peep out of it. It's cooling the CPU (3.6GHz G0), and the graphics (Club3D 8800GTS 640MB) and I'm using three AC AF12025PWMs in the roof, fed from the CPU 4-pin header with three more in the chassis, fed from the 4-pin Chassis header. The fans don't even spin up until the rig has been running flat out for over 2 hours (CPU core is then about 60C and drops quickly back to 45C, at which point the fans shut down again for another 2 hours).
The G70 is more performance oriented, with an 8800GTX in it, and the fans do spin more, but still under 800rpm, so it's also very quiet.