I think i have a few i consider masterpiece.
- Movie: Shutter Island. Martin Scorsese as the director, a movie from Dennis Lehane's novel. Leonardo DiCaprio, Ben Kingsley, Max von Sydow as the actors, the atmosphere and storytelling here is brilliant.
- Light Novel: The Empty Box and Zeroth Maria (Hakomari). This is a good fantasy that gives a frustation and a certain feeling, full of twists and turns and very satisfying to read.
I dunno about painting, but usually the masterpieces i found are in the form of writings, movies or music.