Memorable Oscar moments

I thought it could be fun to look back at some memorable Oscar moments. So here is a warm up for this years award cermony:

Audrey Hepburn winning for Roman Holiday"
John Stewart receiving an honorary oscar
Alfred Hitchcock receicing the Irving G Thalberg memorial award
Charlie Chaplin receiving an honorary oscar
Barbara Stanwyck receives an honorary oscar
Anna Paquin winning Best Supportin Actress for "The Piano"
Ben Affleck and Matt Damon winning an oscar
Hugh Jackman's opening number
Adrien Brody winning an oscar for the Pianist
Nicole Kidman winning best actress for the Hours
Sean Penn winning best actor for Milk Roberto Benigni goes wild at the oscars
Paul Newman receiving an honorary oscar
Blame Canada by Robin Williams
Ben Stiller presenting the Oscar for best makeup
Marlon Brando's oscar win for The Godfather
Kate Winslet winning best actress for the Reader
Martin Scorsese winning an oscar for The Departed
Lord of the Rings winning the best picture and making a clean sweep

There are plenty of other memorable moments, so this is just a selection. What is your favorite or most memorable oscar moment?