Adam Rabalais (deviant art, store) reworks movie posters of famous productions in a minimalistic style. You can buy the Harry Potter collection of prints or any other of his prints in theatrical size at his etsy store.
The Philosopher’s Stone
The Chamber of Secrets
The Prisoner of Azkaban
The Goblet of Fire
The Order of The Phoenix
The Half-Blood Prince
The Deathly Hallows
Tagged: harry potter, minimalistic, posters
pop reimagined 
These should be made into the new adult book covers!