What would you consider the greatest future scientific discovery? Anti-gravity, cold fusion, cure for cancer?

[Atlantean]

True Nanotechnology, cause with nanotech we could cure cancer and all those other things, and we would have the ability to build things atom by atom, and we would be able to mine things using the nanobots more efficiently than traditional mining, there are many other things that would be spawned from nanotechnology.

 

[Hammer]

Cold Fusion I think. Cheap abundant energy would change everything. No more reliance on fossil fuels, no more energy crisis. I would say a FTL propulsion system would be 2nd.