The King and I (1956)

A gorgeous film version of the Rodgers and Hammerstein musical about a widowed British school teacher named Anna (Deborah Kerr) who travels with her young son to Siam (i.e. Thailand) to teach the King's many children.
The self-serving Hollywood need to have recognisable English-speaking actors in key Asian roles was as ridiculous in the 50s as it is now, but Russian-born Yul Brynner somehow makes the role his own, regardless.
The give and take story revolves around a clash of personalities, with the liberated school mistress butting heads with the egotistical monarch.
The theme of slavery is as daring as it gets, but, while it's simple stuff for the most part, it's also hugely entertaining, in the grand musical tradition.

4 etc, etc, etc, out of 5