Honestly? Minecraft vanilla. Partially because it is not an automation game at it's core.
I enjoyed peppering our lands with automated chicken cookers, cactus farms in the sky, gold farms exploiting portal mechanics, and of course an automated transport system.
That it's not an automation system at it's core meant there was inherent value in automating things, to be able to focus on all the other, non-automation stuff.
That it's an game of endless exploration meant I could redo the same (or similar) designs all over when we moved to a new region, and still visit the old machines on journeys.
It was fun to think about how regional peculiarities and peculiarities of specific blocks could be combined to achieve certain outcomes.