Forgive me for being self-indulgent and posting both of my favorite Bollywood films in one sitting but I couldn't choose.
I know what you're asking yourself: which one should I start with this evening? If you need to cut your teeth before heading full force into the Bollywood world I would watch the Bollywood fusion film Bride and Prejudice.
If you're ready to go in for the real thing, the classic Lagaan can't be beat. Warning: there is veeery long cricket game but I guarantee you'll be dancing on your couch before this movie is over.