The ending of the original STAR WARS, not the ceremony per se, the climactic scene where Han pops into the frame in the nick of time and gives Luke the "one in a million" chance of destroying the Death Star. Powerful moment, you can tell audiences were holding onto their seats as John William's score swells and the Death Star is obliterated as Darth Vader goes spiraling out of control.
Also, Chinatown has a powerful ending. Gone With the Wind, Schindler's List, Gladiator, Heat, Butch Cassidy and the Sundance Kid, Indiana Jones and the Last Crusade also come to mind. So many , too many to name really.