I make it seventeen if you count William III and Mary (who reigned as joint monarchs) as two: James I Charles I Charles II James II William III (and Mary) Anne George I George II George III George IV William IV Victoria Edward VII George V Edward VIII George VI Have I missed any out?
I don't think Mary Q of S was ever Queen of England, was she? Again, the question doesn't differentiate between monarchs of which bit of Britain, so a fair point.
I don't get the Mary Queen of Scots suggestion - she didn't rule between the two Elizabeths, just overlapped the first for a while. Her son's another matter.
James I Anne of Denmark
Charles I Henrietta of France
Charles II Catherine of Braganza
James II 1. Anne Hyde 2. Mary of Modena
William III (and Mary)
Anne Prince George of Denmark
George I Sophia Dorothea of Celle
George II Caroline of Ansbach
George III Charlotte of Mecklenburg-Strelitz
George IV Caroline of Brunswick
William IV Adelaide of Saxe-Meiningen
Victoria Albert of Saxe Coburg
Edward VII Alexandra of Denmark
George V Mary of Teck
Edward VIII Wallis Simpson (after abdication)
George VI Elizabeth Bowes Lyon
George I's wife was not queen consort as she died before he came to the throne.
no, she died long after (1726 - he came to the throne in 1714); but he'd kept her in prison for 30 years so I suppose you couldn't actually say she consorted with him.