Personally, having lived in Australia, Vietnam and Dominican Republic, and having visited around 35 in total, western countries have the least sexism.

Muslim countries have by far the most sexism, East Asian countries shame women for being unmarried by a certain age and for being overweight, South African countries have a hyper-masculine, chauvinistic culture in many cases. I haven't visited sub-saharan Africa, but I can't imagine they're beacons of women's rights. Eastern European are more Christian and traditional, expecting a woman to be married and have children by a certain age.

Where's left?