I just bought a new case for my computer (Antec Nine Hundred) and I'm trying to maximize my airflow. The way its setup now is:

2x120mm intake fans on the front
1x120mm intake fan on the side panel
1x120mm exhaust fan on the back
1x200mm exhaust fan on the top

It seems to be pretty cool in there, although SpeedFan is reading a 54C Core and GPU temps, with my computer doing no more than web browsing. My HDD is ice cold at 24C (one of the front fans is almost on top of it, so its understandable) and the ambient temp is reading 38C. What would be better, a fast moving exhaust fan and slow intake fans, or the opposite, or all of them at max speed? All of the fans have speed settings, and with them all at low except the top 200mm fan those were the temps I was getting.

For the record, my computer is a E8400 Core2Duo, MSI mobo (not sure what model), EVGA 8800GT, 4GB GSkill RAM.

Cable management is absolutely perfect. I'm very picky about that and I made sure that on the cables were out of the way, looked nice, and weren't blocking a shitload of air.