The earliest systems were base-60, I think, and I seem to recall that more ancient cultures tended to count to twelve on one hand by putting the thumb on a different finger-bone for each number (three bones * four fingers = 12 possible bones to point to with thumb). It's possible that the current base-10 system came from having ten fingers, but I'd be curious to see a source on that.

As to whether or not a duodecimal system is better than a decimal system, I'm one part undecided and two parts indifferent.