Leica M6 & Nikon F2
For decades, I used an SLR system and a rangefinder system. The two systems compliment each other.
I primarily used the rangefinder when I had to shoot quickly and quietly.
I have three lenses for my Leica rangefinder (21mm, 35mm, and 90mm) and four lenses for my Contax rangefinder (21mm, 28mm, 45mm, and 90mm).
I primarily used the SLR when I had to shoot subjects that were difficult for the rangefinder.
I have the following lenses for my Nikon SLR:
a. ultra wide angle (14mm and 18mm)
b. long telephoto (135mm, 180mm, 400mm, 500mm, and 1000mm)
c. zoom lenses (14-24mm, 28-70mm, and 80-200mm)
d. special purpose (macro, perspective control, and fisheye)
For comparable size, dependability, features, simplicity, and lens quality, the Leica M6 and the Nikon F2 35mm film cameras were my personal favorites.