Gayatri Mantra
Shiva Mantra
Ganesh Mantra
Shanti Mantra
Mantra for Happiness
Om or Aum
Om Mani Padme Hum
Namo Amitabha
I Am That I Am
Ham Sah
I love you, I'm sorry, Please forgive me, Thank you
These are powerful mantras and can transform life of a person who chants.