While I won't dole out the entire list, the prospect of naming the film I consider the most useful is an intriguing task. I've long considered the practice of cinephilia—and, by extension, film criticism—to be a sort of ongoing conversation between oneself and the form. Any criticism worth reading is, in essence, an elaboration of that unique relationship. Consequently, certain films one person finds useful may very well be the exact opposite for someone else. It's within this framework that one can truly learn about another’s relationship with cinema, more so than the nebulous basis of labeling a film the so-called "best."
The most useful film I've ever seen is Paul Thomas Anderson's Punch-Drunk Love. The film was released on November 1, 2002, and like most 15-year-old boys at the time, I was a big Adam Sandler fan. I saw the film because of his name alone. I had only a vague familiarity with Magnolia and Boogie Nights, but had no idea who directed them, and, more importantly, had no clue that it even mattered who directed them. But as I watched Punch-Drunk Love, I very quickly realized that I was not watching an Adam Sandler movie in the sense that I was used to. (Although, in retrospect, Punch-Drunk Love is, in many ways, the quintessential Sandler movie in the way it captures the intangible sense of cynicism that runs through many of his films, but I suppose that's a subject for another blog post.) To be honest, I had no idea what the hell I was watching—the only thing I knew for sure is I had never seen anything like it.
For me, Punch-Drunk Love was the first time I became cognizant of film aesthetics. The film's use of color, sound, and composition are quite deliberate; so for someone like me, who had previously thought movies were only as successful as the stars who appeared in them, its effects were life altering. Looking back, I can safely say that Punch-Drunk Love was the film that kick-started my cinephilia, beginning with a phase that was highlighted by Fight Club, Donnie Darko, and the work of Tim Burton and Christopher Nolan. I find little to no use for those films now, but they were useful stepping stones that lead to the eloquence of Max Ophüls (Le Ronde, Le Plaisir), the poetry of John Ford (Wagon Master, The Quiet Man), and the compassion of Roberto Rossellini (The Flowers of St. Francis, Viaggio in Italia).