The Kiev family, lots of different small variations from types of plastic used on later 303s, different body paneling to different white paint shades of logo (yeah I know you're gonna laugh at that

The Agat family, there are numerous combinations of different types of shutter button, lens ring color and body color:

3 different types of cyrillic logos on Sputnik:

I hope I didn't scare you
Cheers,
Vlad