Undoubtedly, Interstellar has been one of Christopher Nolan's best movies ever. The amount and quality of VFX, SFX, etc. has truly been outstanding. But in truth, the highlight was not the casting of the film. Even though the movie earned big bucks and dominated the box office for a long time, many critics criticized the choice of actors, even with Mathew McConaughey and Anne Hathaway in cast.
Lets start off with the Fan Casting
Benedict Cumberbatch as Cooper
The British heartthrob has been subject to countless number of roles, and seeing him going up and down the universe, would be fairly justifiable.
Elizabeth Olsen as Brand
The eldest daughter of the Olsen family, she would've (probably) been the best choice for playing the role of the astronomer. Her performances in Avengers : Age Of Ultron and Godzilla, shows that she has what it takes to be a space traveller.
Chloe Grace Moretz as Murph
The 18 year old beauty is reportedly dating Brooklyn Beckham which has hit the front pages of many Tabloid magazines and newspapers and if she would've got this role, she would've surely Kick-ed-Ass!
Emily Blunt as Murph (Older)
Her mind blowing performance in Devil Wears Prada, Looper and Edge Of Tomorrow surely would have made her a wonderful beauty with brains, as Murph is a scientist trying to help Professor Brand.
Sir Ian McKellen as Professor Brand
The 76 year old British actor has been a major icon in Hollywood. He has starred in roles of Gandalf in The Lord Of The Rings Trilogy and The Hobbit Trilogy, he has also played the mutant villain Magneto in X-Men and with his latest release Mr. Holmes, I am certain he cannot disappoint us playing a super genius scientist.