श्रीविष्णुसहस्रनामस्तोत्र%E

From Wikipedia

This is the most recited sloka or mantra of Hindus. This is part of one of the greatest epic of world that orginated from the land of Bharatha (India), the MahaBharatha. The Vishnu Sahasranama contains 1000 different names in the prise of the lord VISHNU, on of the most important lords of Hindus, famously know by the names of "RAMA", "RAM" and "KRISHNA".

This contains 100 and more slokas. This is given in reply to the question raised by the great king Yudishtira to his great grand father Bhishma at the time of his last breaths in this mortal world. So, considered to be the most precious of all secrets that man (Mahan) knew.