• Orson Welles – Citizen Kane: 26 years old
• Salvador Dali – The Persistence of Memory: 27 years old
• Kawabata Yasunari – The Dancing Girl of Izu: 27 years old – Snow Country: 35 years old
• Man Ray – First significant photographs: 28 years old
• Luis Bunuel – Un Chien Andalou: 29 years old (via)
• Alan Moore – V for Vendetta: 29 years old (via)
• Steven Spielberg – Jaws: 29 years old (via)
• Kafka – The Metamorphosis: 32 years old (via)
• René Barjavel – Ravage: 32 years old – Grandfather Paradox: 32 years old
• David Lynch – Eraserhead: 32 years old (via)
• Murnau – Nosferatu: 34 years old (via)
• Henri Dunant – International Red Cross: 36 years old (via)
• George Mélies – A trip to the moon: 42 years old (via)
• Gustav Klimt – The Three Ages of Woman: 43 years old – The Kiss: 46 years old
• Marquis de Sade – Les Infortunes de la Vertu : 47 years old

I am getting late… :(

(Any more examples? Please post them in the comments)