Nineteen tone equal temperament (nineteen equally spaced notes per octave instead of the usual twelve) is a popular choice for microtonal composers. It has major and minor triads that are closer to just intonation than in twelve tone equal temperament. It is generally regarded as a more consonant tuning than standard twelve tone equal temperament.
Personally, I find Nineteen tone equal temperament to be somewhat unsettling to work with. Its fifth and major third are both flatter than purely tuned intervals and I usually prefer major thirds that are sharper than purely tuned (5/4) and closer to the Pythagorean major third (81/64).
In any case, I wanted to experiment with this temperament. I came up with a piece for two pianos that could actually be played in real life if the two pianos were tuned to share the 19 tones per octave. I know this is an awkward way to perform, but this is actually done successfully on occasion during concerts. I decided to explore this temperament's darker side. Here is my Rondo in minor modes for two pianos in nineteen tone equal temperament.