Eastman Company: Kodak (Original)

When: 1888.
Why: First "point and shoot" camera for non-professional photographers.

Also, this is the first camera by George Eastman, inventor of transparent photographic film. "Point and shoot" relates to one of the best known slogans in photographic industry: "You press the button - we do the rest". And that was true. Photography enthusiasts had to press button (100 times for 100 photos on the roll) and send camera back to "The Eastman Dry Plate and Film Company" which developed film, printed photos, reloaded camera, and sent it back to customer for $10. In 1888 this pre-loaded camera was offered for $25 (kind of a high price back then), and currently it can go for up to $5000. Check out the Eastman's patent for this camera.

UPD: As it appears, George Eastman was not the "first" inventor of transparent film, nevertheless he popularized it, starting a huge change in the photography history.

Kodak: No.3A Autographic Special

When: 1917
Why: No.3A Autographic Kodak Special was the first coupled rangefinder camera ever

While rangefinders (or "telemeters") were introduced in the beginning of 1900s, they were used as optional accessories and were not linked to the taking lens (non-coupled). Their measured values had to be transmitted to the focusing scale manually.

Coupled rangefinder was "automatic" if I can say so. "Kodak Range Finder" (you can see it as a rectangular box under the lens) had three vertical mirrors in place (camera had to be held horizontally), and image in the middle one was shifting up or down when focusing was changed.

The whole new era started with this camera introduction. Rangefinders became an industry standard until SLR cameras didn't push rangefinders out.