At birth: Males a bit more common. Some countries abort many females. China, India are the largest skewed populations, but Morocco, Spain, Serbia, Greece, Ukraine and some others show up.
UPDATE: Background stats on fertility and sex preferences, an excellent writeup.
As seniors, women prevail everywhere. "And thus the whirligig of time brings in his revenges". Risky behaviour and wars play a role.
Source: Charts Bin