Which one is dangerous? AC or DC?

An AC has a pulsating nature, but a DC is always steady. The green line shows the AC and the red one for a steady DC. 

Before you get confused between a DC and an AC, just think why do you have a voltage stabilizer for a refrigerator. Hmm, well let me tell you because it stabilizes the voltage received. Why does it do so? Because for alternating current, or simply AC, the one that travels through all your appliances at your home, have a change in current, or voltage or emf varying with respect to time. Meaning, AC goes sinusoidally and increases or decreases with respect to time. Then what's a DC? It's simple, boy! A DC is when you light a bulb from a emergency lamp. Or, in your schooling you must have lighted a bulb with a battery.

Okay let's get back to the point. An AC is dangerous. For the illustration, lets take an arbitrary magnitude of voltage, say 200 volts. This value of DC is much less dangerous than an AC. Because an AC would give greater voltage than this, about 311 volts. This is because the peak value is under root of twice greater than the indicated value. The peak value for DC is 220 volts but for an AC its under root 2 multiplied by 220 volts which equals about 311 volts. Now think why would you get shocked when you touch household circuits with hands! Thus an AC provides more shock than DC!

Voltage given out by AC = 0.707 * Indicated Value 

 You can see this Youtube video for further details