The Machinist (2004)
Bale's role as a chronic insomniac who accidentally causes a factory accident is easily his most visually memorable, thanks to the dangerously emaciated appearance he lost more than 60lb to achieve. The film itself doesn't quite live up to the tone of relentless dread it establishes, building to a conclusion that feels a tad contrived, but this is Bale at his most frighteningly committed.