I agree with sarora; there are a lot of kinds of Bollywood movies and movies are constantly changing (e.g. classic 70's era Bollywood was very different form how it is today) so it depends on what you're into. :D

If you want to start off by watching this movie, Jodhaa-Akbar, and you end up liking it, I might recommend Lagaan because it's another period film by the same director (and it got nominated for the Foreign Film Oscar after it come out :D).