Surprised no one has mentioned the Swatch Skins: 3.95mm thin. With case.
And the Titan Edge is an interesting movement: 1.15mm in height. There is also a Titan Slim, 1.75mm in height. Not easy to find pix of the movement though, but they are both quartz movements.
What is especially interesting is that these are coming out of the Tata group in India, out of their Precision Engineering Division (PED), which is where Tata aims to take India into the 21st century.
But still using watch designs of the 1970s, it seems...