An electric drill (AC) has brushes... (mine does, anyways)
As the history bit shows (above), AC is more efficient at being carried over large distances, and that far outweighs any disadvantages. The electrocution factor is there, wether it's AC or DC.
The bad thing about AC is that it induces EMI (electro-magnetic interference), but we've all worked around that. It's bad if you're running logic circuits, with a cheap power supply, but a little .02 uF cap across the power inputs will fix that.
Just for kicks though, you can listen to that 60 Hz hum, pretty much anywhere you are, with the right equipment.
As for motors and pumps, like Tokamac said, if you plug it in the wall, it's AC. As to which one is more efficient, that depends on a number of things, including the power source: batteries are usually the source for DC (toys), and they run well, but the load put on a battery from a DC source is constantly interrupted, and that's bad. On a power supply, the caps fill in the gaps of AC current.
Purely from a power standpoint, I'd agree that 3 phase AC motors are probably the most efficient, but I haven't seen the numbers.
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