Best Dua from Quran

Dua is essentially an expression of submission of faith to God and of one's neediness.

Type I: Du'a al-mas'alah, or the 'du'a of asking.' This type of du'a is when one asks for the fulfillment of a need, or that some harm be removed from him/her. An example would be when a person asks, "O God! Grant me good in this world, and good in the next life!"

Type II: Du'a al-'ibadah', or the 'du'a of worship.' This type of du'a represents a very broad concept. In Islam, every single act of worship includes this type of du'a. Examples would include when a Muslim prays or gives zakāt or fasts.
In Islamic terminology dua is the act of supplication. It is calling out to God; it is a conversation with God, our Creator, our Lord, the All Knowing, and the All Powerful. In fact the word is derived from the Arabic root meaning to call out or to summon. Dua is uplifting, empowering, liberating and transforming and it is one of the most powerful and effective act of worship a human being can engage in. Dua has been called the weapon of the believer. It affirms a person’s belief in One God and it shuns all forms of idolatry or polytheism. Dua is essentially submission to God and a manifestation of a person’s need for Allah.
Prophet Muhammad (peace and blessings of Allah be upon him) said, “A slave becomes nearest to his Lord when he is in prostration. So increase supplications in prostrations.’’ [Saheeh Muslim]
“The supplication of every one of you will be granted if he does not get impatient and say, `I supplicated my Lord but my prayer has not been granted’.’’ [Saheeh Al-Bukhari, Saheeh Muslim]