A’ishah (radiyallahu anha) reports: “I said: O Rasul of Allah (sallallahu alaihi wasallam), should I find myself the laylatal Qadr, what shall I ask of Allah ta’ala? Rasulullah sallallahu alaihi wasallam), replied, Say, “O Allah, Thou art the One who grant pardon for sins. Thou lovest to pardon, so pardon me.”
Note:- This is indeed such an all-inclusive du’a, wherein one begs that Allah ta’ala in His infinite kindness should forgive his sins. If that has been obtained, the path to the akhirah is secure. What more would one require? Imam Sufayan al-Thawri (rahmatullah alaihi) used to say that to keep oneself busy on this night with dua is better that any other form of worship of Allah.
Ibn Rajab says that one should not only remain busy with dua but should also take part in all other forms of worship of Allah, e.g. recitation of the Quran, salah, meditation etc. This latter opinion is most correct and nearer to what Rasulullah (sallallahu alaihi wasallam) has said, as already stated in the previous Hadiths.