Just watched The Eagle Has Landed, a 1976 movie about a Nazi plot to kidnap or kill Winston Churchill in England and it has some of the worst accent attempts I have ever seen. Michael Caine plays a German commando with a silly Krautney accent that comes and goes throughout the film. Even worse is Donald Sutherland, who plays a radical IRA operative who joins the Germans’ plot in order to fight for a united Ireland. Sutherland seems almost quietly embarrassed over how poorly his attempt at sounding Irish is going. Robert Duvall’s attempt at a German accent is only marginally better.
Other bad accents: Kevin Costner in Robin Hood, Keanu Reeves trying to sound southern