The most fundamental of Hindu deities, is the Trinity of Brahma, Vishnu and Shiva - popular deities include Ganesha, Krishna, Hanuman and goddesses like Lakshmi, Durga,Saraswati.
God/Godess
Lord rama gayatri mantra
Om Daserathaya Vidhmahe
Sita Vallabhaya Dheemahe
Thanno Rama Prachodayath.
Meaning of the mantra.
Om, Let me meditate on the son of Dasaratha,
Oh, consort of Sita, give me higher intellect,
And let God Rama illuminate my mind.