My Corsairs Carbide 350r case has also resulted in a near-silent system. There's an SSD in there, but also two HDDs, and they used to make a horrible racket in the old case (I could feel a 'beat' between their vibrations in my desk, with the only physical connection being through the floor!). The difference? The new case has vibration-dampening mounts, and it seems like they do an excellent job.
Also I decided not to go with Intel stock CPU cooler this time, instead using a Coolermaster Hyper 212 Evo. At idle I pretty much can't tell, from sound, if the machine is on. At high load I might notice a little bit of fan noise. It also doesn't hurt that I bought a Gigabyte 'Windforce' GPU based on the recommendations that it's damned quiet even under load, and that's what it turned out to be.