This is not the story you saw when you were a kid. I take that back—I don't know which version you saw, or even if you saw a version of Oliver Twist when you were a kid. It's not a kiddie version, at any rate. Dickens' thieves and murderers and generally terrible people are no Robin Hoods and certainly not the kind of people you'd introduce your friends to unless you wanted them dead or mugged. Bill Sikes is one of the scariest characters in literature, and the others—Fagin and the Artful Dodger among them—though less threatening intially, are ultimately no less frightening.
Part detective story, part social manifesto, entirely some of the best prose you'll ever read (Ever.), everyone has some knowledge of the plot, but until you've read it in all its visceral glory you don't know Oliver Twist. (The fact that anyone could even contemplate translating this into a musical of all media is unfathomable and depressing.) There is brutality—it isn't just dogs Sikes beats with his cudgel. There is genuine love—Mr. Brownlow is motivated by more than just a sense of duty. There is humor (though decidedly darker than is standard for Dickens) and there is sentimentality and there is fear and there is happiness. In short, there is life.
Life is what Dickens evokes in each of his brilliant novels. In Oliver Twist he shows its darkest aspects, with little of his usual counterbalance with displays of humanity and warmth. Those elements are here, but they are shadowed by the horror and the suffering his characters endure. This isn't a work without hope, by any stretch—but it is an exploration of themes everyone knows intimately and seldom wants to come to terms with. Dickens brings us to such a confrontation with grace, wit and finally power, creating something so beautiful we can't look away, something so heartbreaking we can't help but be changed.