I have traveled to all the continents apart from Australasia and NZ, and although I visited India, have I not seen as much of Asia as I would like . . . Yet.
My favorite destination to have visited so far is India. It's a difficult place to adjust to and visit, and you are certain to suffer from culture shock big time, but it's so enigmatic, rewarding and worthwhile. If you want to be shocked, or feel the need to escape from your regular 8 - 5 workday, or maybe long for something that will change your life, then visit India.