The humans in the Code Geass universe, despite their immense technical accomplishments, do not have nukes of any kind. Or at least, not until one of Einstein's grandchildren finally makes one.
Much like the Tech Tree example above, this example is due to the fact that Sakuradite-assisted electrical propulsion systems were much more efficient than internal combustion engines. Thus, the effectiveness of electric-based systems extends to chemically propelled firearms as well; being replaced instead with Magnetic Weapons.
The Golden Tribe of Heroic Age was apparently so enlightened, they did not need to come up with the concept of numbers, or at least that's the theory Mobeedo comes up with.
Buck Godot: Zap Gun for Hire establishes that every single technology, artform, odd tradition, bizarre hangup, etc. of humanity was already known to the galactic community by at least one other species having invented it. Except... Popsicles. Nobody else had ever thought of freezing liquid on a stick and eating it that way. Our parties immediately became immensely popular.
In one Donald Duck story, some aliens appear who never invented money. This leads to hilarious problems when they commit Grand Theft Me on Donald and "he" meets Scrooge.
The Thermians from Galaxy Quest don't know the concept of fiction, period. As a result, they mistake TV series like Galaxy Quest and Gilligan's Island for real events. This is related to the fact that they also didn't know what lying was, until they met the Big Bad (who incidentally figures out the plot and finds it hilarious).
It's been pointed out by Scary Movie III that the aliens from M. Night Shyamalan's Signs have mastered interstellar travel but have trouble with wooden doors.
They also seem to have never come up with the idea of hazmat suits. (They appear to have landed on a planet where pretty much everything is made of flesh-dissolving acid and decided to wander around completely naked.)
Prince of Space features aliens invading because of this trope. The invaders from Krankor have superior spacefaring technology, but their fuel technology is inferior to Earth's; they need the new formula for rocket fuel to start a true invasion of the stars (they have only one working ship, as opposed to the fleet they could fuel with the new formula).
The aliens in Independence Day have superior technology in many respects, but their actual computer technology lacks any sort of safety protocols to prevent intrusion. A lone man with a laptop is able to hack into the network of the mothership, and by proxy, the entire fleet, shutting down their shields.
This is possibly justified given the aliens appear to have a hive culture - they may not have ever needed to have computer security prior to encountering humanity because they've never met anyone that would or could do that.
Can seem literally true in Star Wars - with most of the Empire's ground weapons being equipped with complex walking systems so they have high centres of gravity and are vulnerable to tripping. However, there are wheels in the Star Wars universe.
Based on the fact that scrolls are used by several groups, including the Sith when Holocrons aren't available, one finds that hard to believe.
Many of the planets that are important in the canon and the EU don't really have much in the way of trees. A reliance on parchment or polymer sheets over paper wouldn't be surprising even if they had invented it.
More generally, galactic civilization is a few thousand years old and based on inheritances from some Abusive Precursors. The majority of civilizations and many entire species are younger than artificial intelligence and interstellar highways, so some gaps in their understanding of the more basic technologies isn't terribly surprising.
A literal version of this trope is Spielberg's remake of War of the Worlds, where the aliens are shown in the basement of a house, quizzically playing with the wheel of a bike, in an homage to the original novel (see the Literature section below).
They're also touching and even licking everything. It would appear they also have no concept of germs, which, of course, ends up being their downfall.
In The Hitchhiker's Guide to the Galaxy, Arthur Dent can never seem to find a cup of tea. At one point, a computer is so stumped by the concept of tea that it effectively shuts down.
And then there's the alien race mentioned which invented the deodorant spray before the wheel, so at least for some time, they'd fit this trope. In their case, it's amusingly justified, since they're a species with fifty freaking arms.
Ford Prefect came from a planet that never came up with sarcasm.
Has an interesting twist in The Conquerors Trilogy by Timothy Zahn. The aliens have nearly indestructible ceramic hulls and instant FTL communication. The humans have radio communications and can track FTL ships. So, it's more like "each race has unique strengths and weaknesses."
In The War of the Worlds it is hinted that the tripod-using Aliens skipped the invention of the wheel. There's an odd variation on the trope regarding disease - it's described that their own hygienic procedures were so successful that they've effectively forgotten what pathogens are, so have no defence against them.
The Discworld books invert this with a few throwaway mentions of slood - something which is supposedly easier to discover than fire, and only slightly more difficult to discover than water.
The precursor civilization who used golems for literally everything only ever used wheels as children(s toys.
One of the early books had a Mayincatec civilization who had chariots, but the wheels were square. A well-meaning explorer tried to correct their mistake and ended up as a sacrificial prisoner.
Discussed in The Tripods prequel novel When the Tripods Came. The Tripods are capable of interplanetary travel but still use plain old white light to scan areas rather than infrared or radar. One character points out that technological progression is not the same between cultures and points to the Mayans, who had an advanced road system but no wheels.
Clifford D Simak's story "The Big Front Yard" has aliens who never invented paint.
In the Eternal Champion story by Michael Moorcock, where the human's technology level is roughly Middle Ages, the elf-like non-human Eldren have invented many 20th Century modern weapons of destruction, including futuristic ray guns but have never succeeded in making a flying machine. Ekrose (who, in another life, has much experience with modern technology) is surprised at this gap in their knowledge.
A literal example occurs in Poul Anderson's story "The Three-Cornered Wheel", where an alien civilization lacks wheels because their religion considers the circle too sacred to put to vulgar mundane use.
The whole plot of Harry Turtledove's short story "The Road Not Taken" and its sequel "Herbig-Haro". Antigravity and FTL travel turn out to be so ridiculously easy to discover that it can be done at the hunter-gatherer level, but the science involved is so different that it doesn't work with any other form of science or technology, and once you have antigravity and FTL, you don't need many other forms of science or tech, so they are never developed. You end up with civilizations that essentially stall at whatever technology level they were at when antigravity is discovered. Humans find out about this when they are invaded by aliens, the current dominant local interstellar power, who march out of their anti-gravity propelled starships and attempt to conquer the planet with muskets and linear battle tactics. Given that they attempt to invade late 20th/early 21st century Earth, it's a short invasion, and humans promptly spread out to the stars with their superior technology. In the sequel, humans run into a species that had managed to carve out a small interstellar civilization without discovering antigravity and FTL, so now they are the ones caught in the antigravity trap.
The wizards from Harry Potter, despite having at least one train and at least one bus, do not use electricity or anything else discovered/invented in the last couple centuries or so, even when it would be much easier than what they do (ball-point pen, anyone?). This is Hand Waved by magic interfering with technology/electronics, but there are so many mechanically simple inventions that they could be using... and if an auto can be magicked enough that the electric starter isn't an issue, then clearly it's not much of an impediment.
Played overly straight where wizards, even though there is a substantial population who were "Muggle-born" (born and raised in the "real" world), don't even comprehend everyday items.
Even Muggle-born are only raised in the Muggle world until age 10, after that spending only relatively brief periods outside the Wizarding World for the rest of their education. How much does a 10 year old really understand about technological devices? The magical devices that imitate mundane devices (alarm clocks, and so on) are rather like the kinds of things a child might imagine technological items SHOULD be like.
Considering how many wizards and witches marry Muggles, it's remarkable that more of them aren't exposed to technologies in getting to know their spouses.
The Race from Harry Turtledove's Worldwar can fly between solar systems, possess nuclear weapons, and have incredibly powerful computers, yet they have no concept of chemical weaponry, or any sort of battle-field appropriate gas masks - their closest invention, filtration suits, are for cleaning up nuclear waste.
In Everworld, it's noted that the Coo-Hatch have invented a kind of super-durable steel that can cut through just about anything, but have never discovered gunpowder. Until the protagonists accidentally help them do that.
It's also worth noting that David points out their grasp of something as comparably simple as knot-tying and the use of a pulley leaves much to be desired.
In Animorphs, alien character Ax is actually surprised that humans invented books before computers, as he considers the former to be the greater achievement.
The Yeerks have also apparently never used projectile weapons, possibly because they stole most of their technology from species that were already far more advanced. Visser One has to remind the others that they can, in fact, be quite effective.
The Hork-Bajir Chronicles show that this is indeed the case. The first Yeerks to leave their planet attack the Andalites with stone age weapons, plus one stolen Andalite shredder. They escaped with assorted Andalite technology and developed their own weapons and spacecraft from there.
The Tran from Alan Dean Foster's Icerigger trilogy justifiably never invented the wheel, because they're natives of an ice-covered world where it's easier to move things on skate-blades and skis.
In Dragon's Egg, the technological turning point in Cheela civilization was the invention of the sleigh, as opposed to the wheel. Justified in that the Cheela homeworld has such extreme gravity — it's a freaking neutron star after all — that no axle could be lifted off the ground and remain intact.
In Larry Niven's Ringworld novels, natives sometimes find it tricky to draw the line between intelligent and non-intelligent hominids, as different species' earliest technological advancements don't always correspond. For example, some aquatic species use flaked stone tools but have never discovered fire.
In H. Beam Piper's Little Fuzzy series, the legal standard for establishing sentience is the ability to build a fire and to use language. Complications ensue when humans encounter the Fuzzies, who have fur, live in a temperate environment, and prefer their food raw (thus eliminating the need for fire). They also don't appear to speak until it is discovered later that they do have a complex language, but their vocalizations are beyond the range of human hearing. However, the Fuzzies do have other signs of intelligent culture—toolmaking, ritual burial of the dead, hunting/gathering behavior—so much of the plot hinges upon whether the Federation's legal standard for sentience should include the Fuzzies.
Star WarsNew Jedi Order inverts this, as everyone in the known galaxy has never seen a book before, but the Chiss use them.
Played for laughs in the Confederation of Valor series. The H'san apparently think humans are cool because we're the only species in the galaxy to invent cheese.
Live Action TV
In one episode of Star Trek: Voyager, the crew meets an alien race which is quite advanced, but was completely oblivious to the concept of music before hearing the Doctor sing. Even after they did become fond of it, they seem to enjoy the music primarily because of its mathematical rather than its artistic aspects.
Data on Next Generation once mentioned a race that developed a written language before the use of speech or gestures.
Played for Laughs in Doctor Who, where the Doctor once pointed out the fact that humans are the only species in the universe that has invented edible ball bearings (Sweets with hard outer candy shells. M&Ms and things of that nature).
Also in Torchwood, where Jack tries to cheer up Owen during a team camping trip.
Jack: "No other species in the universe goes camping. Celebrate your uniqueness."
In the pilot episode of his series, Alf examines the Tanner's toilet and exclaims "Interesting concept."
In Stargate SG-1, the Asgard, who are ridiculously far ahead of humans, have to enlist the Earthlings' help to fight the Replicators, against whom Asgard beam weaponry was useless, but guns worked wonders. Thor mentions that the thought of using chemical propellants to fire a slug of blunt lead simply never occurred to them. Presumably, they hadn't used propellant weapons in several million years and didn't think of using them.
There's also the fact that all Asgard are clones whose consciousnesses have been around for thousands of years. This tends to lead to some rigidness in views, although they're still damn good scientists.
Somewhat amusingly inverted in Babylon 5. According to G'kar, it is one of the great mysteries of the universe that every known race has created a foodstuff identical to Swedish meatballs ("Breen" in the Narn tongue).
The inhabitants of the Matoran Universe in Bionicle react with bafflement when they discover a parchment left behind by their Precursors and wheels affixed to the feet of the ancient warrior Umbra. Despite knowing what wheels are and several creatures having caterpillar tracks for legs, their ground vehicles all had insect legs, and only one vehicle (the Destral Cycle) was ever shown to canonically use wheels for their intended purpose.
Some Civilization games allow players to progress up the tech tree while skipping at least one basic tech. It can be rather enjoyable to achieve flight without understanding electricity, even if the units look no different...
Done literally in the sci-fi scenario of Civilization II: The Test of Time. One of the earliest alien technologies is "circular supports", reading the flavour text reveals that they copied this technology off the humans, who call them "weelz". The text goes on to express bafflement that they invented interstellar travel before coming up with this idea.
The humans of the Fallout series have never invented the transistor, so their advanced technology looks like it came out of a 1950's computer lab, despite having giant robots, nuclear-powered cars, energy weapons, and AI.
The Drengin don't have such a thing as fiction - rather, they can sense pain and other negative emotions, which give them pleasure. Ergo, their only form of entertainment is causing pain/fear/etc. in others.
On a more literal note, this is why the Terrans pioneered Hyper Drive, which allows fast interstellar travel without the massive limitations imposed by the stargates used by other races.
Unfortunately, humans in this 'verse didn't develop common sense. The first thing they do after inventing the hyperdrive is give it to all aliens.
The Covenant use stolen AI to pilot their ships, as Cortana discovers when she cannibalizes one.
The Covenant in general don't seem to truly understand the advanced technology they wield.
They also cripple said AI with the same religious limitations as their flesh-and-blood followers. When Cortana starts messing around with the Covenant ship's settings, vastly improving its FTL drive and weapons, the Covvie AI "jumps out" and calls it heresy.
In Mass Effect, this worked to Humanity's advantage, as under the Treaty of Farixen, they were limited in the amount of Dreadnoughts they were allowed to build. Their response to this imposed restriction? To introduce the concept of a Carrier to the galaxy, then proceed to build as many as they liked, safe in the knowledge that the treaty didn't specify anything about them!
Apparently, The Mercury Men have sophisticated technology; they can transport between worlds and manipulate gravity. But going from planet to planet via chemical-propelled rockets is something new and threatening to them.
A Treehouse of Horror episode had Kang and Kodos coming to Earth to share their alien technology, which included the most advanced video game they'd ever created: Pong.
The Incans, despite being a considerably large and powerful empire, really never did invent the wheel. This makes more sense when you realize that they lived in rocky, mountainous areas, where wheels would be, in a word, useless. They used pack alpacas instead.
More precisely, they never adopted the wheel for practical use. Some wheeled children's toys have been found.
The problem was that they lacked suitable traction. Llamas and alpacas are smallish, delicate creatures with limited endurance, and while they could be somewhat successfully employed as pack animals, they've couldn't pull a cart worth a damn.