It is a tradition for the best man to give a speech celebrating the newly married couple, and Captain Picard did just that; his heartfelt speech to the happy couple was admired by all in attendance, most notably Deanna. (Star Trek Nemesis)
"Duty. A starship captain's life is filled with solemn duty. I have commanded men in battle. I have negotiated peace treaties between implacable enemies. I have represented the Federation in first contact with 27 alien species. But none of this compares with my solemn duty today...as best man!"
- Captain Picard's opening words in his speech regarding his close friends Deanna and Will