A film's villain is one of the its most important elements, for the villain gives the story its stakes and obstacles. As such, getting the villain right is very important and many, many movies, especially Hollywood blockbusters, have been fatally undermined by messing up in that department.
A common way movies fail with their villains is by getting entirely the wrong actor on-board to play them. Frequently offending are the movies that bring in a prestigious character to play a hammy, cartoonish villain, which usually goes about as well as one would imagine... Not very well at all.
10. Russell Crowe - Les Miserables
Les Miserables might be one of the weaker Best Picture nominees of the decade, but it does at least benefit from a collection of outstanding performances from a terrific cast... with one huge exception.
Despite his shortcomings as a person, Russell Crowe is a frequently strong actor but this part as Inspector Javert, the principal antagonist of the film, just didn't suit him.
As seen in films such as Gladiator and LA Confidential Crowe is great at playing tough, powerful male characters but in this case he's constantly alternating between this style and trying, unsuccessfully, to realise Javert's morally complex and softer elements, making this performance a confused mess.
The biggest issue of all is Crowe's awful singing, which ensured he stuck out like a sore thumb among the rest of the cast. In a rather endearing manner, Crowe openly agreed with the criticisms of his vocals online, so he was obviously aware this wasn't one of his better roles.