The Top 5 Greatest Kings in Indian history, in my opinion:
5. Kanishka I (r. 127-151 C.E.) - for creating perhaps the most diverse and internationalist state in Indian history. Kanishka himself was a Buddhist of Central Asian origin, but within the borders of his empire virtually every philosophy and religion of the known world flourished, including Hinduism, Zoroastrianism, and Hellenism. His empire stretched from North India to Persia and Central Asia, being one of the only Indian kings to rule such a territory; as a consequence the Kushanas directly controlled the lucrative Silk Road trade between East and West and reaped immense profits. The arts flourished and wealth was in abundance.
4. Samudragupta (r. 335-375 C.E.) - for restoring the imperial splendor of Magadha and ushering in India's Golden Age. Considered "India's Napoleon", he crushed the Sakas and Kushanas, long the dominant powers in South Asia, and extended Gupta role over much of the subcontinent. He also patronised the arts and sciences, paving the way for India's greatest thinkers and scholars; the highly prestigious centres of learning at Nalanda, Varanasi, Takshasila, and others drew migrants and pilgrims from all over the world. It also during this time that extensive cultural and commercial links began to be established with Southeast Asia, eventually leading to the rise of Indianised kingdoms in that region.
3.Shahanshah Jalaluddin Muhammad Akbar (r. 1542-1605) - for pioneering modern liberal secularism and universal tolerance in an age that badly needed it. The Ibadat Khana, or house of worship, hosted a wide diversity of philosophers and scholars from all religions, where they debated various matters regarding life and universe before the emperor. The abolition of the jizya and other discriminatory taxes and a policy of equality towards all regardless of belief allowed the empire to prosper. India's cultural achievements, especially in architecture, reached their zenith. The empire was also incredibly wealthy; it was said that Akbar's annual revenue in 1600 exceeded in value Britain's entire treasury in 1800.
2. Chandragupta Maurya (r. 320-298 B.C.E.) - for uniting Bharatvarsha into a single entity for the first time, and becoming an inspiration for countless Indians of the past, present, and future. With the assistance of Chanakya, perhaps the greatest statesman to be born in this part of the world, he first overthrew the corrupt Nanda dynasty of Pataliputra, reinstated a new dynasty in his name, and went on to unite the various peoples of India. His career culminated with the conquest of Afghanistan and defeat of Seleucus Nicator, one of Alexander's own generals.
1. Samraat Asoka Maurya the Great (r. 274-232 B.C.E.)