Sahih Bukhari Volume 004, Book 052, Hadith Number 041.

Narated By Abdullah bin Masud : I asked Allah's Apostle, "O Allah's Apostle! What is the best deed?" He replied, "To offer the prayers at their early stated fixed times." I asked, "What is next in goodness?" He replied, "To be good and dutiful to your parents." I further asked, what is next in goodness?" He replied, "To participate in Jihad in Allah's Cause." I did not ask Allah's Apostle anymore and if I had asked him more, he would have told me more.