Ocean’s Eleven (2001)
Soderbergh's 2001 Rat Pack remake. Clooney, Pitt, Damon, Roberts, Gould.
Brad Pitt broke through in Thelma and Louise in a role lasting a few minutes, and then spent much of his career deliberately working against the face, taking supporting and character parts when leading roles were available.
Twelve Monkeys, Fight Club, Burn After Reading and Inglourious Basterds are all performances by someone enjoying not being the handsome one. He won Best Supporting Actor for Once Upon a Time in Hollywood, playing a stuntman with almost no interiority.
His production company Plan B financed 12 Years a Slave, Moonlight and The Departed, which is a more consequential contribution to American film than most acting careers.
Se7en, Moneyball and The Assassination of Jesse James are the ones to argue for. The last of those is the most underseen thing he has done.