Quote Originally Posted by David Brown View Post
OK, getting back to the OP question; I don't think this is really answerable, but I'll play:

645 fixed lens: Fuji rangefinders

645 interchangeable lenses: Mamiya/Pentax/Bronica

6x6 rangefinder : Mamiya 6

6x6 TLR: Rolleiflex, Minolta Autocord

6x6 SLR: Hasselblad, Bronica

6x6 “budget”: Yashica TLR, Kowa 6

6x7 fixed lens: Fuji 670

6x7 interchangeable lens rangefinder: Mamiya 7

6x7 SLR: Pentax 67, Mamiya RB/RZ67, Bronica

6x9 fixed lens: Fuji 690

6x9 “press”: Mamiya Press, baby Graflex

6x9 view camera: any view camera with a roll film back

... let the games begin!
Yes! Just append one:

6x6 SLR: Hasselblad, Bronica, ROLLEIFLEX (SL66 and related)