1) Mahatma Gandhi's suggestion to include Dr Ambedkar in the Constitution Committee & Jawaharlal's decision to give Dr Ambedkar full freedom in drafting the Constitution. India chose to become a secular democratic republic with universal adult franchise. It was the greatest landmark in Indian history.
2) Jawaharlal's decision to form India's Atomic Energy Commission way back in 1947!
3)Indira Gandhi's bold decision to free Bangladesh in spite of threats from USA.
4) VP Singh's decision to implement Mandal Commission report. That revolutionized the power sharing for good. By implementing Mandal Commission, VP Singh timely defused a mighty bomb & saved the nation!
5) Rajeev Gandhi's decision to usher an era of telecommunications & computers (the information technology). Indian passport gained respect only because of Rajeev's IT dreams!