The Day the Earth Stood Still all the way to the freakish incoherence of Plan 9 from Outer Space, though most of them are formulaic genre adventures with a relatively limited field of characters to pick from and a certain tendency towards stock footage anti-aircraft guns firing at cutaway shots of flying saucers.
Of these formula-driven alien invasion movies, I am convinced that the finest must be 1956's Earth vs. the Flying Saucers, and not only because its flying saucers are pretty much the best ever. They were created by Ray Harryhausen, of course, and it is truly the case that for the man behind Dynamation, they're not terribly complex or characteristic: no fantastic, otherworldly creatures with nightmarish feature and 98 points of articulation all moving at the same time, no roaring dinosaurs to warm every 10-year-old heart. Just pie-pan shaped discs with a band on top that spins counterclockwise, and a few bits that sometimes extend out. Harryhausen claimed this as his least-favorite among the films he contributed special effects for, and I imagine that's part of the reason why. Nobody ever mentions the flying saucers when they're talking about his career highlights, or anything like that.
Nevertheless, they are the best. I suspect that it might owe to the fact that the animation itself was unusually straightforward and simple by Harryhausen's standards, but the effects throughout the movie are unbelievable well-integrated into the rest of the film, in some of the absolute best process shots of the man's career. Flying saucers ambitiously composited into shots of the White House, into stock footage of battleships exploding, and beautifully married with the footage actually filmed for the movie itself: there's a shot early on where one saucer is on the ground, with a force shield surrounding its landing strut, as its inhabitants mill about, and it's on an army base, and all the different layers and optical effects that went into making that moment fit together so perfectly that you straight-up forget that you're looking at special effects.
And it's not just the technical quality, but the ebullience of the saucers' activity that make them and their film stand out. Even if you haven't seen the film, surely you've seen the clip of a flying saucer hitting the Washington Monument and knocking it over, or of one crashing into the U.S. Capitol dome and exploding. Those both come from this movie, in its exemplary final ten-minute attack on Washington, D.C., one of B-movie science fiction's all-time best alien action sequences, and really, that's all the argument you need: Earth vs. the Flying Saucers is the pinnacle of its genre because it has the best depiction of widespread, saucer-derived destruction, and that is deep down inside all that these films want to provide (sure, you can read all the cultural subtext you want into it; but it's the same cultural subtext from every genre film of that decade, and so it frankly shouldn't count). The one that provides the best of that is itself the best. Q.E.D.
The good thing is that Earth vs. the Flying Saucers ends up having more to offer than just those breathtaking final 10 minutes. Not a great script, exactly - a great script would have been mostly an imposition on this scenario, anyway - but an airtight one, utterly free of bullshit and padding (it's a film whose economy is such that, having established in the first scene that the two leads were married the day before, it only references this fact once more in 83 minutes, trusting that we'll understand what the emotional stakes are), with every beat contributing to the overall development of the plot. The story was adapted, from Maj. Donald E. Keyhoe's non-fiction book Flying Saucers from Outer Space, by Curt Siodmak (who did not also write the screenplay), a writer whose best work is awe-inspiringly clean and precise, so this kind of mechanical excellence really doesn't come as a surprise; but it absolutely gives the film a leg up over everything else you could name in the same idiom, resulting in a movie that lacks even the idea of lag time.
Befitting a movie made at the very first flicker of the Space Age, Earth vs. the Flying Saucers is absolutely dazzled by scientific advances: the hero, Dr. Russell Marvin (Hugh Marlowe), is a rocket expert working with a kind of proto-NASA to launch a dozen orbiting satellites (a word too fancy for the film to trot out) that will permit all kinds of wonderful research. The big narrative beats all revolve less around the military beating the tar out of them aliens, but from Marvin or an associate making some critical research breakthrough that gives them a leg up on the invaders; not until Star Trek reached the air ten years later would impressive-sounding gobbledygook be used to resolve so many crises, with such deep, passionate love for The Concept Of Science's ability to fix things. I deeply admire the film for this. It could only have come out of a singularly anti-cynical moment in American history.
Undoubtedly, the film is an acquired taste, or at least best suited to a particular kind of viewer. The human element is almost nil: Marvin's new wife Carol (Joan Taylor) avoids being portrayed as the usual '50s sci-fi female ninny only because nobody in the movie emerges with any real personal life to speak of, or shading beyond their profession. At one point, a character we've been set up to like as much as anybody in the film is turned into a brainless zombie, essentially, and while the curt brutality with which director Fred F. Sears (whose career somehow managed to include not only this shining triumph of '50s genre filmmaking, but also the humiliating disaster of '50s genre filmmaking The Giant Claw) presents this development is shocking and therefore effective, it's not really because we feel particularly sad for this man, more than we'd feel for anybody under the circumstances. Characters are vessels here; raw survivalism is the point of the movie, and only the cheap B-movie trappings keep that fact from making the whole thing dark and grim and brooding. That and the sheer movie-awesome potency of the visual effects.
It's not sophisticated, the film's meager politics are a bit confused and under-explored, and though it is a rousing adventure about the triumph of humanity, it's tech-worship keeps it from being humanist. And yet part of me loves Earth vs. the Flying Saucers a little bit; for its efficiency, and its directness, and how absolutely perfect it is at telling only exactly the story it cares to tell in the most engaging way possible. It's not any kind of B-picture gateway drug, but as a well-established admirer of the form, there's nothing about this film that doesn't please me.