Cambodia: King Norodom Sihamoni
Cambodia is one of many countries with more of a ceremonial king rather than one who actually rules the people. King Norodom Sihamoni took over the role in 2004 after Thailand's Royal Throne Council hand picked him (which is the custom with any new king). He was in competition with other male royals — even though he was the son of the reigning king at the time (who abdicated after 60 years on the throne).
He might've been an unconventional choice seeing as he was a professional ballet dancer, who lived most of his life in France, but he won the job. Although he is now a figurehead for the country, Sihamoni previously played a role in politics acting as Cambodia's ambassador to UNESCO.