26. 'The Man in the Iron Mask' (1998)
This was the first DiCaprio film to be released after the success of Titanic, and it became a hit for that very reason. But with all due respect to Monsieur Dumas, it's dreadful: A dumbed-down, star-studded period piece about the Four Musketeers' attempts to replace the sneering, playboy King Louis XIV with his long-imprisoned twin (both played by DiCaprio). The young actor seems out of his element here, and not even the veteran actors surrounding him – Gabriel Byrne! John Malkovich! Gerard Depardieu! Jeremy Irons! – can't do much with the dopey script.