The Gayatri Mantra is most famous among all the mantras, all the Vedic mantras. The entirety of the Gayatri is then again condensed into Om. So you can just chant Om and it's as good as chanting the Gayatri or chanting all of the Vedas. Of those who deceived, I am gambling. They should put up a statue of Krishna in Las Vegas to represent God.
In this series of talks, Swami Sarvapriyananda unfolds the highest truths of Vedanta through the study of the Bhagavad Gita (The Song of God).