Even though Calvin Candie doesn't appear until we're midway into the film, he somehow demands the entire story around himself. DiCaprio crafted a memorable performance for someone who wasn't technically a "main character."
Azog the Defiler - Manu Bennett
Azog the Defiler, also known as The Pale Orc, is one of the key villains in The Hobbit. Manu Bennett brought the role to life quite literally. Everything about this character was done in CGI, so he had to work extremely hard to make sure that the mannerisms and facial features looked good.
Bennett also starred in 30 Days of Night and Beta Test. He is certainly the most menacing character in The Hobbit, even with all of the post-production work. It's a shame that he's technically unrecognizable, but he is revered in the film industry for his work as Azog.
The Bride in Black - Tom Fitzpatrick
How do you make a horror-bride as scary as possible? Hire an older man to play the role! Tom Fitzpatrick played the Bride in Black, a key horror icon in the Insidious franchise. The bride's backstory stems from the main character's tortured childhood when his mother would force him to dress in girl's clothing and respond to the name "Marilyn."