What is the coolest minecraft contraption you have made?

A decision to never ever play minecraft, which I cherish.

Dirthouse… With a neat mass-block transportation lift in it

I'm still new to all these redstones. Working on it.

And you, Etho?

A skele spawner that makes skeles 1 shot kills, then you can flip a switch and a piston moves a block that makes the skeles go down 1 more block and die, with a hopper to automatically pick up whatever they drop.