SAFER+
A 1998 block cipher that competed for AES, lost, and then lived on in billions of Bluetooth devices.
SAFER+ was developed by James Massey and colleagues at Cylink and was one of the AES candidates. It had 128-bit blocks and keys of 128, 192 or 256 bits. It fell out of the competition, but the Bluetooth specification adopted it for authentication and key generation, in the functions E21, E22 and E3.
It is one of the more ironic footnotes in cryptographic history: a cipher that did not win a competition but became the backbone of a standard used every day. Anyone curious why Bluetooth pairing works the way it does should start here.