Some of the most popular videos of the year, including Olympic madness; Nick Clegg's musical apology; Prince Charles's weatherman audition; and Felix Baumgartner's jump into history. Elsewhere Boris Johnson gets caught on a zipwire; Sacha Baron-Cohen spills Kim Jong-il; Jeremy Hunt loses the end of his bell; Joey Barton auditions for 'Allo 'Allo; and everyone else channels Gangnam Style