(Please see as well other fine answers for more computers fitting the list)
I guess we can put them in four categories (in descending order of application):
Machines with Different Language in ROM
The early models of the Soviet BK-0010 series had FOCAL in ROM. BASIC was available as an add-on module. Later models starting from BK-0010.01 already had BASIC in ROM.
Clean Computers
And then there would be the classic Sharp MZ-80 series with no language in ROM. Clean computers from the start, BASIC or any other language had to be loaded from Cassette. Quite successful around the world.
With Separate but Included Language ROM
Similar but less fitting are machines that had no language fix build in, but supplied (usually) BASIC separate on a (ROM-) module which was always included when buying the unit. After all, everyone would have had it plugged in ... at least until switching for something more sophisticated. The Exidy Sorcerer of 1978 might be the earliest example. An even more prominent example are Atari 400/800 (as mentioned) of 1979.
Systems From a Time Before Language Were Included
The same, of course, goes for many very early systems, from single boarders to S-100, including hobbyist systems like Heathkit H8 or the Apple 1. Remember MS' first BASIC for the Altair was delivered on paper tape or cassette. But then again, these are so early, that the term 'home computer' may not really apply.
Close Runner Ups
Also, while not really an 8 bit home computer, the Newton had it's NewtonScript interpreter in ROM.