We tend to think of the effect of individual movies on the business and culture of making other movies to be pretty binary: Bad movies beget bad, good movies beget good. Truth is, many of the worst, most annoying trends that catch on in the film world do so because they originated in good, even great films, but were copied by lesser successors looking for a shortcut to greatness.
What follows is a sampling of good movies and the bad trends they unwittingly gave rise to:
O' Brother Where Art Thou?
The Crime: Digital color-correcting.
This modern classic comedy/folk musical is one of the biggest hits of the Coen Brothers' distinguished career, but it was also a technological innovator. It was one of the first feature films (and the most high-profile at the time) to scan all of its footage into digital format before editing, and thus the first to take full advantage of the ability to digitally color correct every aspect of the onscreen image.
Since the placing of certain color tones directly opposite others will cause them to pop, color correcting quickly became a post-production trick on almost every big movie. This quickly gave rise to the now ubiquitous orange and teal phenomenon, the easiest color timing scheme that has now become the go-to design motif of every other damn poster, trailer and piece of key art you've seen of late.
The Damage: Pretty bad.
Filmmakers like Michael Bay have stretched the orange and teal scheme across entire films, creating a kind of ugly action genre alternate universe where everything is painted blue-green and it's always sunset.
The Crime: Sanitizing the space opera.
Credit where it's due, George Lucas' industry-reshaping megahit did a lot to legitimize the sci fi/fantasy genre. Unfortunately, legitimacy sometimes comes with a price.
Prior to Star Wars, the sci fi genre, particularly the more fantasy-inflected variation called "The Space Opera", was largely inseparable from a certain amount of seediness and soft-core sleaze. Sci fi writers, unsurprisingly not known for being the most romantically confident of humans, frequently packed their stories with the surreal byproducts of frustrated fantasy. Heroes found an amusingly vast number of clothing options on planetoids inhabited by no small number of uninhibited species and a surprising (or maybe not) number of genre entries could be boiled down to "how we traveled to the planet of the this-or-that maidens, and how much crazy alien sex we had when we got there." It was no small part of what earned the genre its disreputable tag for a good chunk of its existence. Even Star Trek had plenty of time for shirt-ripping hunks and green-skinned alien concubines amid Roddenberry's future tech and social justice ruminations.
Star Wars: A New Hope, on the other hand, pretty much drops all of that. There are really only two women of note in the whole film, Leia and Aunt Beru, and they both fill out almost entirely nonsexual little sis and mother roles (one of which, yes, is appropriate in hindsight). Not that there's any room for it in the tightly plotted feature, but apart from Han Solo's rakish leering you don't get much sense that anyone is having sex of any kind in the Star Wars universe, or is even particularly interested in it. For all the talk of gun-toting Princess Leia as an early feminist archetype, she can also be seen as being a boy's fantasy figure rather than an adult male's: the "one of the boys" girl who can hang out and won't spoil the fun with icky mushy girl business.
To be fair, this lack of matters of the flesh probably helped the film secure its place as holy writ in the eyes of youngsters; it had all the spaceships, aliens and laser swords, none of the mushy stuff. It also took mushy stuff out of vogue for the rest of the genre and as an ironic side effect, reinforced the boys' club atmosphere more strongly than ever. If you weren't going to have women in the story to wear the armored space bikini or get chained up by the baddie, might as well just dump their presence entirely, seemed to be the prevailing wisdom. Within a few short years, the female presence in youth-oriented sci fi had gone from "Women Are Decorations" to "Women? What Are Those?"