I am a big fan of 12vdc power. I know, it probably seems like a weird thing to be a fan of, and frankly, it is.. but it's proven to be incredibly useful nonetheless. I will list some of the reasons I am such a fan of 12vdc power.
12v DC is a universal power. 12v is the same in the states as it is in Japan, England, Australia, or anywhere else you are. With 12v, you don't have to worry about the line frequency, whether the power is single or split phase, etc.
12v is fairly “safe”. At such a low voltage potential, it isn't easy to be shocked by it. Now, I'm not suggesting anyone grab the terminals of a car battery, but frankly, unless your hands are wet, it likely wouldn't do anything anyways.