Which is more dangerous: AC or DC power?

AC can flow through capacitance, DC cannot.

Our bodies has some resistance as well as capacitance. When DC is applied our body only offers resistance. When AC is applied, due to the capacitance a higher current will flow compared to the same voltage in DC.

At very high frequency AC, the body becomes poor in conduction due to skin effect.

While it may take a much higher voltage for DC to be fatal, once you reach such high voltage - DC is much more dangerous than AC. As the current it delivers is continuous unlike AC which goes up and down.