Dr Strangelove
A good premise - of the fallibility of the US defence system which mistakenly send a bombing group to destroy Moscow - nice touches like Pickens' cowboy hero persona - even to the point of plunging to his own death astride a nuclear missile. Several classic scenes and characters, among them George C Scott's red menace-fearing General and Sellers' "Don't you think I'm upset, Dmitri?" phone call with the drunk Russian Premier.
Released at the same time as Failsafe (almost identical plot - sans satire) by the same studio, which resulted in legal action by Kubrick. The studio agreed to throw all their marketing weight behind Strangelove and Failsafe subsequently bombed.