It is a great film adaptation of the classic King novella
Rita Hayworth and the Shawshank Redemption.
It's pretty faithful to the source material too, although King's character of 'Red' played by Morgan Freeman in Darabont's film, is a red-haired Irishman in the book (hence the nickname!)
I couldn't imagine anyone else other than Freeman playing the role however, and is possibly his best acting role to date.
This was one of my favourite films growing up, and I still love to watch it today.