This thread cracks me up so thank you all for your incredible description. My M4, Rolleiflex and Olympus Pen, Pen S and Pen W barely make a sound so I guess that doesn't count. Unless we're talking silenced fire arms. If so then I would say the Pen series are the most silent. I like the sound of the Rollei 35 quite a bit. That click and the rewind has this je ne sais quoi 🙂