Varanasi (Benaras) is nice --make sure you attend the dusk prayer at the river banks where they pray for world peace and float oil-lamps down the river.
Nearby Sarnath where Buddha taught the dharma very peaceful place also a must see. 1 to 2 days for Varanasi/Sarnath
Amritsar and the golden temple are another worthwhile attraction. 1 day.
If you have more time her is a hidden gem that most foreigners and even Indians do not visit. It is Aurangabad (1 hour flight from Mumbai) which is the home of Ajanta and Ellora caves built from around 10 BC. The sculptures and paintings are well preserved and is a UN word heritage sight. You can skip Mumbai as there is nothing to see there ( I went to high school there so I know a bit about Mumbai). 2 days from Mumbai
Then comes the south. The south has been almost untouched by foreign invasion and is the home of the original civilization. Tamil Nadu (capital Chennai) is the heart of South India and is a great place to visit. The Mahabalipuram beach temple, Madurai, Tanjore, Kanchipuram. 3 days from Chennai.
Adjacent state of Karnataka (Bangalore capital) has Belur, and Halebid and Mysore. 2 dyas from Bangalore.
Kerala on the SW coast of India has great beaches, tranquil and tropical lush.
Feel free to contact me for any India information. I dont live there now but spent most of my youth there.
Edited by vkumar, 11 September 2012 - 18:44 .