Laughing and smiling
Since I became a Muslim it never happened that the Messenger of Allah (Peace and blessing of Allah be upon him) saw me without smiling at me. Allah's Messenger (Peace and blessing of Allah be upon him) once said: "Through this gate a man will enter — one of the best men of Yemen, whose face bears the touch of an angel." Then I came in.

Imam al-Bukhari, Moral Teachings of Islam by Imam al-Bukhari, Abdul Ali Hamid, translator