I love the sound a camera (a real camera, with a real mechanism) makes when you take a photo, whether it's a real shutter or the mirror or a DSLR, it's just not the same if there's no noise or worse still the laughable sound effect added to a point-and-shoot or a phone.

The best sound of all is winding on the film in a totally manual SLR like my old K1000, you know you've taken a photo when you hear and feel the gears turning.

The are a few occasions at work when I wish my camera had a silent function, but I'll put up with that for the awesome sound of  a mirror going up and down at 8 frames per second.