Add to the list, late (1990's) Cipher 1/2" tape streamers. Kind of
odd, really--a controller board with both a Z8002 handling the drive
smarts and an 80c188 handling the SCSI interface.
It would not surprise me if the '186 could also be found in some
laser printers. I've found CPUs from the 68K family to the NS32016
in them.
The great thing about the 186 was the 20-bit DMA controller, but only
two channels of it. The 8089 IOP featured 20 bit DMA, but was a very
different fish--fairly expensive and more involved to interface. One
wonders why Intel, over the life of the ISA bus, never came out with
a 24-bit version of the 8237.
--Chuck