[Pazuzu]

AC is easier to make (it naturally comes out of rotating generators)
AC is easier to use for most of our large appliances (motors like AC)
AC goes to 0 power every cycle, which means that the heat produced on a line (lost power) is sqrt(2) less than the lost heat from DC
AC changes directions each cycle, so the magnetic field formed collapses and changes direction each cycle, so it tends to average towards zero, in how it affects actual objects (like your brain)
It's easy and pretty efficient to go from AC to DC, it's very lossy going from DC to AC
AC can be stepped up to very high voltage/very low current for thin wires and massive power transfer easier than DC can be stepped up.

There's probably some aspect of self-inductance that makes one better than the other, but I don't care enough to figure that out. I think that AC actually gets worse when the self-inductance is calculated, since the magnetic field is changing. DC systems have no inductance, the magnetic fields are static.

At very high voltage, with large wires spread well apart, over long distances, both types of electricity are pretty much equal.