Here's a nice quiet build I did over a year ago in an Antec 300 case.
Case: Antec 300
CPU: Intel E6750
RAM: 2 x 2GB Team Dark DDR2 1066
Motherboard: Gigabyte GA-P35-DS3L
Video Card: MSI HD2600XT Fanless Heatpipe
PSU: Antec Neo HE550
HDD: WD Green 500GB
HSF: Thermalright Ultra 120 eXtreme with Artic Cooling AF 12025 PWM
Intake Fan: Noctua NF-S12 1200
Exhaust Fan: 120mm Antec TriCool
Blowhole Fan: 140mm Antec TriCool
It is a very quiet case by most people's standards, but i'd have to say that on the whole, I wasn't very happy with the 300 case. I have seen much better cheaper cases.
The 2 TriCool fans the 300 comes with are fairly rubbish. When the case was new, the 120mm fan would not always start up on the lowest setting. This was a known manufacturing fault and Antec offered to send me a new fan if I would send them a photo of the old fan with one of the blades snapped off so they would know I wasn't going to reuse it. I didn't bother, but after a few months of running in, the fan worked properly. The fans still make too much noise for my liking.
I'm quite happy with how neat the insides of the case are on this build though.
Mods to case: Fan grilles cut out, holes cut for wiring.
Still to do: Elastic mount the hard drive. Replace all the fans with quieter ones (mainly the TriCools, becuase the 12025 on the Heatsink hardly ever starts up and it only runs very slowly).