This won the Oscar for Best Picture, and (as I type) is #48 on IMDB's list of the best movies of all time. So, yeah, it's pretty good.
In case you haven't heard about it: it follows three Indian slum youths, Jamal, his brother Salim, and Jamal's true love Latika, over the course of years. Jamal and Salim are orphaned early in the movie by religious rioters and, with Latika, fall in with a very bad crowd.
The whole movie is framed by Jamal's appearance on India's version of Who Wants To Be A Millionaire, where he does surprisingly well. So well, in fact, that he's detained for fraud by the cops; his story is told in flashbacks, as his interrogation relates the experiences that led him to know the answers to tough TV-show questions.
There's a lot of violence and realistic depictions of the degrading conditions under which poor people live in Mumbai/Bombay. But there's also occasional humor. (A scene in a call center where Jamal calls on his knowledge of all things Scottish is flat-out hilarious.) And, overall, it's a great story of love, betrayal, perseverance, and suspense. (Yes, it's sentimental and contrived, but so what?)
Things I learned: (a) Indian cops are apparently fine with torturing suspects; (b) Indian movie gangsters are, in important respects, similar to American movie gangsters; (c) the Indian host of Who Wants To Be A Millionaire is an evil mutation of Regis Philbin; they could make a pretty good movie about him.