Antec Performance One P180 Mid-Tower Case
 

As far as quiet goes, the P180 is perfect. The 3 speed TriCool fans, the triple layer side panels and rubber bushings on everything adds up to a VERY quiet PC. Currently the only thing I am able to hear when the case is sitting on my desk a couple of feet from me is the PSU fan and the 80mm heatsink fan. Once I get my water-cooling system installed I imagine this system will be almost 100% silent.