Alan Rickman as Severus Snape, 1-8
With lips permanently curled in derision, and a voice like satin soaked in bile, this Welsh-Irish character actor was J.K. Rowling's choice to incarnate Snape. Honestly, who else? Rickman, 64, achieved his first and lasting prominence on stage as the maleficent Valmont in Les Liaisons Dangereuses, and on screen as the purring baddie Hans Gruber in the first Die Hard. Snape, a Hogwarts classmate of Harry's sainted parents, and the Potions teacher in the first five films, is promoted to Defense Against the Dark Arts this time — a measure of Dumbledore's somewhat perplexing trust in him. To this crucial character Rickman brings a lovely mixture of wit and threat: in Half-Blood Prince he provokes the tensest shivers and the biggest laugh.

• Growing Up with Harry Potter