What to add to the other 5 star reviews? I watched these three films straight after reading Golding's trilogy and enjoyed them immensely.
Script-writer Leigh Jackson ("Warriors"), who tragically died before the project was finished, efficiently extracted the best dialogue from the books, streamlining the plots very effectively for film. The cast are uniformly excellent, but Benedict Cumberbatch is simply outstanding in the lead. Edmund embarks on more than the physical journey of his life during his year aboard the unnamed ship. That we are able to trace every subtle movement of his emotional development is due to this actor's incredible technique and intelligence. Also superb are Victoria Hamilton as Miss Granham, and Daniel Evans as the Rev. Colley, both beautifully judged performances that light up the screen. Joanna Page (Stacey from "Gavin and Stacey") makes a delightful Miss Chumley. In fact this is casting at its absolute best: Capt. Anderson, Charles Summers, Devrel, Benet, Pike, Brocklebank, Zenobia, Sir Henry... all superbly brought off the pages of Golding's masterpiece!
Costume, sets, direction are all top notch. And I recommend the short "Making of" extra that comes with Disc 2. Great work, BBC!!