[fancyPantsZero]

Ableton Live.

The way the UI design packs tons of control into a simple, flat interface. The way everything happens in realtime. The way everything can be routed and automated and chained.

Even though I'm a shitty musician, I love this program so much.

[meowface]

I'd argue Bitwig is even better designed. It was started by some employees at Ableton who split away from it.