Heads I win, tails you lose

Queen Victoria. Half Penny - 1889. Reign 20 June 1837 – 22 January 1901
Edward VII. One Florin - 1908. Reign 22 January 1901 – 6 May 1910
George VI. One Shilling - 1939. Reign 11 December 1936 – 6 February 1952
Elizbaeth II. Sixpence. 1953, Reign 6 February 1952 – present

Since the time of Charles II, the direction in which the monarch's head faces on coins has changed with every succeeding monarch with the exception that the heads on the coins of successive monarchs George V, Edward VIII, and George VI all face to the left. Edward the VIII's were not formally issued - though some did get into circulation.

The same does not apply to stamps - the monarch always faces left.