My old NSK-3300 and Seasonic 300w SFX were getting a bit long in the tooth, so I decided to get a new case/PSU (wanted to go ATX this time around) and upgrade a few other parts.
Aluminum probably isn't the best from a noise standpoint, but I love the aesthetics and the fit and finish of Lian Li cases. With low speed fans things stay pretty quiet. The T-LM14B-2 top panel w/140mm fan mount and BS-03 PCI cooling kit with 120mm fan were purchased to improve air flow, especially in the PCI area where it's kind of lacking with the default PC-A05NB.
Lian Li PC-A05NB
Phenom II X4 955 @ 1.230V
4x2GB Corsair XMS2 DDR2-800
MSI Hawk R5770 @ 1.125V
OCZ Vertex 2 120GB
2x WD Caviar Green 1TB RAID 1
Front, rear, and PCI 120mm fans are at 700RPM (using the ULNA). The 140mm fans on the CPU and top exhaust run at about 800RPM (again, using the ULNA adapter they were provided with). The Hawk R5770 fan is set to auto, gets up to about 70*C while gaming and stays pretty quiet. The GPU is undervolted slightly, which helps keep the fans from ramping up as much. CPU is undervolted as well.