In agreement with others above, my vote goes for...
Acoustic insulation, but don't jam it in tight. Needs to be loose to work.
Resilient bar.
As heavy/dense a boarding as you can go, or multiple layers.
For best performance don't hard-join to the walls. Mastic as per
@Pagey. Just needs to be air tight.
I planked my dining room ceiling many moons ago. It's 19mm thick but narrow boards so not to painful to fit, though I still made myself a board lifter as I was solo.
For soundbloc on ceiling, you need a board lifter (cheap on ebay and re-sell it, or hire). For 15mm soundblock, you'll also need a priest and a chiropractor.
Fireline should also work as it is more dense, double board it.