After my previous visits to Paris, I had always gone home with the pain of having missed the Musee d'Orsay for lack of time. I made do with admiring the beautiful building (designed by Victor Laloux for the Universal Exhibition of 1900) from the outside. During my most recent trip to Paris, I made a resolution to not to leave without visiting the museum.
After waiting in a mile-long queue in the rain (it rains constantly in Paris, a secret the French rarely let out), I finally fulfilled my wish.
Don't start at the bottom, but rather go straight to the top floor to begin your visit. That way, you won't miss amazing works like the Gates of Hell by Rodin.