I really liked this simple chant for meditation from Awakening the Buddha Within: Eight Steps to Enlightenment: Tibetan Wisdom for the Western World by Lama Surya Das.
May all beings have happiness and the cause of happiness.
May all beings remain free from suffering and the cause of suffering.
May all beings come to remain unseparated from the sacred joy and happiness that is totally free from sorrow.
May all beings come to rest in the boundless and all-inclusive equanimity that is beyond attachment and aversion.
And this one:
We rejoice in the good fortune of all. We rejoice in the virtuous good deeds and accomplishments of others. We put an end to covetousness and jealousy. We forgive and accept others, and put an end to feelings of ill will and enmity. Blessings to the world. Blessings to ourselves.