DS9 "In the Pale Moonlight"

So I lied, I cheated, I bribed men to cover the crimes of other men. I am an accessory to murder. But most damning thing of all, I think I can live with it.

Brooks' delivery makes you able to buy the subversion of every moral espoused in 40 years of Star Trek. I don't know if it would land as well if you weren't already steeped in the show, but it's incredible to watch the first time if you are.