HOW OFTEN DOES a first novel win the Man Booker? With a quick internet check, we learn that Adiga was preceded in that accomplishment by Keri Hulme, DBC Pierre, and Salman Rushdie (if we don't count Grimus). An odd assortment, I'd say. The White Tiger is the goods, though.
Adiga has found a terrific voice for the narrator, for instance; the whole novel is an immense memo to (then) Chinese Premier We Jiabao, explaining how free market capitalism works in India, which turns into an account of how Balram Halwai became the successful entrepreneur he is today. Balram's voice begins in bluster, swings into satire, and finally plunges into confession. He makes every page interesting.
As in, say, The Great Gatsby, our theme is self-invention; unlike Gatsby, in The White Tiger we hear directly from the self-inventor himself. Self-invention is never easy, but Gatsby had something of an advantage in being in the country that invented it, rather than in a country with a millennia-old caste system, where your ancestors have been in the same village doing the same work for centuries, and your very name broadcasts your lot in life. Balram has to generate genuinely terrifying amounts of escape velocity to get out of what he was born to it--and that is just what he so memorably does.
That yeasty old class ferment of prejudice and ambition that proved so heady for Balzac and Dickens is still cooking away in the sub-continent, it appears.