Excellent list in "The Telegraph."  A few additions come to mind:

1. Queen Mary I--dubbed "Bloody Mary" after her father, Henry VIII, split with Rome over his divorce from her mother, Catherine of Aragon.  When she became Queen, Mary tried to re-establish Roman Catholicism as the official religion and persecuted numerous Protestant clergy and followers.  In all, more than 200 were executed during her reign.  After Mary's death, her sister, Elizabeth I, restored the Protestant religion in Britain.

2. Then there were the murders and suspicious disappearances of members of the Royal Family, including:

 
- King William II was killed in 1100 with an arrow while hunting in the New Forest. Supposedly an accident, it has been suggested that he was shot deliberately on the instructions of his brother Henry.
- Edward II was murdered in 1327 at Berkeley Castle on the orders of his wife, Isabella.
- Henry VI was murdered in the Tower of London in 1471.
- Edward V and his younger brother were imprisoned in the Tower of London in 1483 and never seen again. Their fate remains a mystery but the two princes are believed to have been murdered.on orders from their uncle Richard III.
- Henry VIII executed two of his six wives, Anne Boleyn in 1536 and Catherine Howard in 1542.
- Charles I was executed by Parliament in 1649 following the Civil War.

3.  The abdication of Edward to marry Wallis Simpson.  They were later known as the Duke and Duchess of Windsor and made some questionable decisions in their conduct after being banned from England--going to meet with Adolf Hitler and praising him after their visit was one example.

4.  Finally, there have been "scandals" involving Sarah, the Duchess of York, who was accused of overspending, plagarizing her book "Budgie" and not giving the monies she'd promised to charity to those she'd pledged to help, and generally "seeing" men other than her then-husband, Prince Andrew; Prince Andrew's own dalliances with the former porn star, Koo Stark; Princess Diana's revelations--denied at the time--to writer Andrew Morton which portrayed the Royal Family in an unpleasant light; her son, Prince Harry, dressing up as a member of the Third Reich for a costume party; and, of course, the ongoing affair of Prince Charles and Camilla Parker-Bowles--now his wife.  Princess Margaret, the Queen's sister, also caused some headaches with her behavior with Roddy Lewellyn while still married.  "Lesser royals" like Princess Michael have been plagued with rumors of affairs with other men and making money by charging to be in attendance at various events and Marina (don't know if she has an official title) was pregnant and planned to have the baby out of wedlock till the Queen interceded.

To say the least, it's a fascinating family--one which caused the Queen to call 1992 her Annus Horribilis because of the divorces and separations of her daughter, Princess Anne, and her sons, Princes Andrew and Charles.