There are many facets to traveling in India. All depends upon how, where and when you go. India changes every square mile, the seasons change fast and the ethnic and cultural diversity changes at every nook and corner.
If you are interested in a historical tour of India than your destination is routed through Delhi, Agra and Rajasthan, for the Taj Mahal, Delhi Fort and Kutab Minar. In Rajasthan, Udaipur and Jaipur offer many historical monuments notably the forts of the Rajput rulers.
Madhya Pradesh or Central India offers many historical destinations of which the Khajuraho Temples are the best known and tourists throng in large number to visit the Kama Sutra on temple walls.
For ecotourism Madhya Pradesh offers amazing Indian wildlife including the best places to see the Indian tiger. Namely Kanha, Bandhavgarh and Pench Tiger Reserves. The bird life is amazing as well here and one can study around 250 plus bird species.