The Lost Weekend

In essence, "The Lost Weekend" is a simple story: an alcoholic who considers himself a failure spends a weekend spiralling further and further down, with the aid of numerous bottles of rye whisky, only to come out of it in an unlikely, Hollywood-hopeful surge of optimism. There are three things that make the film worth seeing.
First, Ray Milland. I only know one other film starring this actor, Hitchcock's ingenious "Dial M For Murder", where he delivered a believable foppish psychopath. His role here, however, is much more demanding, and he plays it perfectly, mixing humor and despair effortlessly. The supporting cast is fairly OK, but pales in comparison.
Second, Billy Wilder. Every time I see yet another movie by this director, it seems to stand apart from the other ones, and this is no exception. The camera work is almost Hitchcockian from time to time.
Third, the topic. 1945 test audiences reportedly balked at the gritty, nihilistic atmosphere of the film, which I guess didn't fit the end-of-the-war euphoria. Leaving the sappy ending aside, it's a dark and haunting portrait of an addict even today, made worse by the fact that this is actually a likable guy.