The Atari 2600 created the home console market in 1977 and is the reason cartridges exist. Pitfall!, Adventure and Space Invaders all started here, and its 128 bytes of RAM make it the least demanding system on this list by a wide margin.
Runs effortlessly on every R36 model. Many titles expect a single-button joystick, so the extra buttons go unused.
The R36 handheld family runs Atari 2600 titles with perfect compatibility out of the box.