As far as festivals go, there is none other more widely celebrated and more joyous as Diwali, India’s most visually spectacular festival, celebrated on the darkest night of the year. Here's a short video from National Geographic talking about the significance of Diwali and experiencing Diwali in India.
This is a spectacular 10 day Hindu festival celebrated to honour the birth of the beloved Hindu elephant-headed god, Lord Ganesha. Ganesha is worshiped for his ability to remove obstacles and bring good fortune. He is the God of wisdom and is honoured at the start of rituals and ceremonies as he's also considered the God of beginnings.
This short video from BBC will give you a glimpse of the magnitude of this very popular festival.
Holi also known as the "festival of colours", is considered as one of the most celebrated festivals of India and it is celebrated in almost every part of the country as a national holiday. As the video below suggests, you have to be there to experience Holi. Words cannot describe it, but this video does a pretty good job...