The core logic (if you can call it that) of the Getter Rays from Getter Robo, being the energy of evolution itself. Their sole purpose is to grow larger and more powerful, and this often results in Humongous Mecha on an enormous (and in some cases galactic) scale.
Ku Fei's artifact; a staff that can instantly expand to many times it's original size, meaning anyone standing at the end of it when it expands is effectively hit by a train.
Subverted in Fullmetal Alchemist, when Envy transforms into his monster form against the Flame Alchemist, Roy Mustang.
Mustang: I can't believe you made yourself a bigger target. You really thought bigger would be better?
In Night Wizard, Emotionless Girl Akari usually wields a BFG, but during one of the final episode, she briefly upgrades to a RIDICULOUSLY oversized ANTI-FLEET weapon. It's so big, she needs another wizard to handle the reloading. Rather than firing from the hip as is her general style, she finds it necessary to carry it on her shoulder... and it's the size of an interstate bus.
The movie version goes even farther, featuring a Combining Mechaformed from several of those. Then plays with it by making this mecha the reincarnation of their founder come back from the grave (again).
The "Timmy" demographic in Magic: The Gathering is defined as caring first and foremost about massive creatures that can slam the opponent (or, in a broader sense, any spell with a huge, sweeping effect), and Magic sure has no shortage. The classic "biggest and baddest" is Leviathan; other notables include the devastating Dragon Tyrant, the unspeakably large Denizen of the Deep, and the majestic Godsire. The single biggest, baddest, most monstrous monster in the whole game, though? The dread goddess Marit Lage, who is so powerful she can't even be summoned by normal means.
Spoofed in the (deliberately silly and not tournament-legal) Unglued expansion set with the B.F.M. (Big Furry Monster), a creature so big it doesn't even fit onto a single card.
Foxtrot: Roger buys a four-foot tall cell phone from "Mobytel" ("I assume the "Moby" is short for mobile"). It turns out to not work out so well as both the ends are too far away to actually have a conversation.
Jurassic Park III's Spinosaurus was bigger than T. rex, because... well... T. rex just wasn't cool enough any more. Which was more dangerous in real life is debatable (and since they never lived at the same time, no actual confrontations ever happened), but in the movie...Spinosaurus is bigger, so naturally it wins the fight.
Interestingly, the Velociraptors in the first movie were much bigger than in reality (they were actually Deinonychus, but "Velociraptor" sounded cooler) while the dilophosaur was much smaller. But it could spit poison, which the real ones most likely could not, so...
Death Stars in Star Wars. According to The Other Wiki, Death Star I had a diameter between 120 and 160 km. Death Star II was anywhere (depending on the source) from 160 to 900km! Death Star I was already basically impervious to direct attack (it just had that pesky thermal exhaust port, a design flaw that was removed for Death Star II), so it's not like they needed to make the armor thicker. Ordinary weapons might break through a few non-essential decks, but to hit anything important you'd have to get dozens of kilometers down. Good luck chipping away at if for that long before you eat a superlaser. Granted, Death Star II had a better laser, but was there really any other reason for it to be so much larger?
It probably says something that all of the Original Trilogy movies, along with Revenge of the Sith, opened with a Star Destroyer, which is more than a kilometer and a half long. Other big contenders are the Executor (so big, it used ENGINES bigger than Star Destroyers), Ackbar's five-kilometer-long flagship, the three-kilometer Trade Federation Lucrehulk battleship, and the seven-hundred-meter Acclamator troop transport. And that's just the movies; the EU has things like the Maw Installation◊, seen in comparison to a prototype Death Star, Centerpoint Station, which was 300 kilometers long, and the Galaxy Gun◊.
Godzilla is king of the monsters. Are you king of the monsters? No. You're too small.
To his credit, Belloc is more open-minded about his successor.
In Bill and Ted's Bogus Journey Bill and Ted were nervous about the Station twins knowing what they were doing. The twins did a Fusion Dance, turning into Big Station. Suddenly there were no more worries. Apparently Big Station was more obviously a great scientist than the Station twins?
The Götterdämmerung in Iron Sky, the flagship of the Nazi space fleet (It Makes Sense in Context). The guns on that monstrocity can take out a tenth of the Moon with each shot. However, the ship is too overpowered. Since the Nazi computer technology is so far behind, their ENIAC-sized machine can't hope to run all of the Götterdämmerung's systems. Then they get ahold of a smartphone.
Subverted in Sergey Lukyanenko's novel Genome with the Taii - an ancient galactic superpower whose strength waned after a devastating war with another equally-powerful race. Their colossal ships are still allowed to patrol space that now belongs to younger races, but they are little more than relics of ages past. It is mentioned that a tiny by comparison human destroyer is able to completely incinerate one of these Taii battleships with a single volley.
Played completely straight by Bolos, which are remarkably large, AI-guided tanks. Later marks mass more than most battleships.
John Keefauver's story "The Great Three-Month Super Supersonic Stack-Up of 1999" satirically depicted a near-future with planes so huge that they could be stacked up for weeks. ("Six feet longer than ten football fields! Six feet wider than three football fields!")
Played with in Stargate SG-1: Our heroes have discovered that the Tollan have somehow manufactured their own Stargate. In order to stroke his shrinking ego, all O'Neill can manage to say is, "Ours is bigger."
In the Victorious episode "Survival of the Hottest", the main characters (minus Cat) get stuck in an RV on a particularly hot day. Tori suddenly remembers that she brought a battery-powered fan, searches her bag for it and presents a tiny, two-bladed fan.
Tori: Here it is! André: Oh, stop. Trina: That's it!? Robbie: That's your fan? Tori:(insulted) Yeah... Beck: It's not big. Jade: It's an embarressment! André: You teased us... Tori: Okay... Okay, fine, then I guess I just won't turn it on. (Everyone protests desperately) Tori: Yeah, yeah, now you like my tiny fan, don'cha!?
This is the basic principle behind the design of most, if not all, weapons, vehicles, and equipment in Warhammer 40000.
Also most, if not all, Orks.
In the Star Wars Saga Edition RPG, there's a simple way to estimate the challenge level of any given starship. Is it a fighter? It's probably low-challenge. If it has a CL of 16 or higher, there's a 99% chance the vehicle in question can cause a nasty localised eclipse, followed by reducing the eclipsed area to ash with its Frickin' Laser Beams.
A fan-made, impossibly humongous ship apparently dubbed the Imperium "Ultra" Class Star Destroyer with all the fixin's inspired someone to write a status report concerning the maiden flight of the SDSD Freudian Nightmare and all the problems that would come with maintaining said impossibly huge ship. It's hilarious.
The Lyran Commonwealth military revolves around this trope in BattleTech. It has led to the (mostly spoof) meme that a typical Lyran scout lance consists mainly of their lighter assault 'Mechs (like the 80-ton Zeus).
Throughout Sword of the Stars. Large guns are better than small guns. Large hulls have better colonisers, sensors, command & control, and tankers than small hulls. Large planets are easier to defend and more productive. Better engine systems are larger, too.
One exception, though. Only small guns can target and destroy incoming missiles and Attack Drones.
Before the Valcazard was the Geant Chevalier from Super Robot Wars Destiny. In that case, it was more an instance of longer is better, clocking in at over one hundred meters long. And it's a Real Robot. One longer than Ideon is tall.
The fundamental military strategy of the Global Defense Initiative is to build big tanks. Then upgrade and build to bigger tanks. Then put bigger guns on those bigger tanks. Then build a really, really, really big tank to eat up resources at once and then build even more giant tanks. GDI takes the concept of More Dakka and applies it to armor like no other.
The fundamental military strategy of the Soviet Union in the Red Alert series is to build big everything.
Heroes of Might and Magic III featured "grail structures" that could be built at only one town on any map. Most of them tended to be very tall (the Colossus, the Warlords' Monument) or very wide (Aurora Borealis). They were easily better than any other non-troop-producing building you could produce, because a) they were free to build if you met the requirements; b) you could build a grail structure as well as a normal structure on the same turn in the same town, c) most of them were very tall; PAY ATTENTION.
Master/Hell Mel from Lunar The Silver Star has, as part of his personal weapons collection, an axe larger than him...and he can wield it one-handed.
In most of the Dynasty Warriors and Samurai Warriors games (and thus, by extension, in Warriors Orochi), each warrior can obtain 4 different tiers of weapons. Each higher tier has higher attack, awesomer appearance, and a noticeably bigger size — hence, in those games, bigger really IS better. However, as a result, a lot of the warriors winds up with HILARIOUSLY oversized weapons on the fourth tier. For example, "The Devil" Shimazu ends up with a warhammer whose head is bigger than his (impossible muscled and heavily-armored) torso, Sun Ce ends up with a pair of Tonfas that are longer than his legs, Kunoichi's Dual Knives turns into Dual Longswords, and so on....
Star Ruler both uses and averts this. While it is true that bigger subsystems take more damage, bigger weapons deal more damage at greater ranges, bigger bays can store more stuff etc., there are also downsides to upsizing such as weapons taking longer to reload.
Asura's Wrath subverts this. The first of the Seven Deities, Wyzen, starts out as a big Fat Bastard, and at each stage that Asura beats him, he draws upon more Mantra power to become bigger. He goes from being the size of a tank to about a hundred meters tall, and when Asura punts that form into space, he calls upon a huge amount of Mantra to transform into a planet-sized form. He then proceeds to crush Asura with an index finger the size of a small country. Asura, being Asura, just gets pissed and punches Wyzen so hard that the force travelling up his arm makes him explode. Immediately afterward, the rest of the Seven Deities are shown as annoyed and scornful of Wyzen for wasting so much power because he was convinced that being bigger meant he was more powerful.
Played straight in later instances, like when Deus fuses with the Karma fortress to become Sakra Devanam Indra Deus, who dwarfs even the above mentioned Wyzen, as well as Augus's sword being able to extend his sword to up to 380,000 KILOMETERS in length.. Then n the True Finale of part IV Nirvana D Lc, Asura uses the same Mantra Reactor Wyzen and Deus used, now implanted into his body, to dwarf even them, and parry a "small" laser that would still have engulfed the planet, from Chakravartin's Giant Vessel form, which is so big it makes Galaxies seem like Small dots by comparison.
Played with in Schlock Mercenary. Schlock loses his BFG, and is offered a new model which is much more powerful and doesn't need to warm up. On the downside, it is smaller, and doesn't make an ominous hum when warming up. Schlock manages to find another of the old model. To be fair, Schlock uses both the size and the ominous hum as much for intimidation as he uses the gun for blasting things. Although he does like blasting things.
Engines. The bigger, the better, especially if you want the huge block just to cruise around the town. It is possible to squeeze 750 hp out of a little 2.4 liter engine — Formula 1 does it — but doing so needs royal trainloads of Phlebotinum and at least US$3,000,000.
Sports cars usually have V-8 engines, twice as much as your average family car.
The Bugatti Veyron, the second-fastest production car in the world, has a ~1000 hp W16 engine!
The Ultimate Aero TT is also geared to top out at 270 MPH.
The Dodge Challenger SRT-8 has a 6.1-liter V8 that comfortably hits 425 hp, while costing less than 5% of what an F1 engine costs.
There's also the Chevrolet Corvette C6 Z06, which makes 505 hp from a 7-liter V8.
Any muscle car fits this trope. There's no replacement for displacement, after all.
Formula One in the 1980s subverts this somewhat. Per the rules, forced-induction engine sizes were capped at a minuscule 1.5 liters. Despite this, it was quite common for such engine to be able to produce up to (and beyond) 1,500 hp. The designers simply increased the size of the turbochargers to ridiculous extremes.
The Cadillac Eldorado with its 8.3 liter (500 cu in) all to brake emissions legislation.
Empire State Building!
World Trade Center!
And they still keep trying to top it... see this list for several up-and-comming examples, topping out at the 1.25 miles high Shimizu Mega-City Pyramid near Tokyo.
Stalin wanted to turn Moscow into a monster city, as evidenced by his plan to build the enormous Palace of the Soviets, which for that time would be the largest free-standing man-made building in the world. Oh, and did I mention that roughly 1/6th of the building was to be a giant statue of Lenin?
It would've been built too, if he hadn't chosen a site that turned out to be over an underground river. You really don't want to build a building that large on top of a river. They did dig a massive hole in the ground for the foundation before the project was scrapped.
Great Wall of China
Pyramids of Egypt
The Colossus of Rhodes.
The mythical Tower of Babel.
The pyramids of Teotihuacán and Chichén Itzá.
Stonehenge which is, after all is said and done, nothing more than a big sundial.
Balls of String. There are multiple places claiming to have the World's Largest Ball of String, and probably a very thriving rivalry among them all.
Inverted with most high-tech devices. People are more impressed with the Macbook AIR than the room-sized behemoth computers of yesteryear (except in a "whoah, they used to be that big?" sense).
In an unusual, and clever, application of this trope, the USSR did this with a substantial amount of their military weaponry during the Cold War, making it larger than equivalent NATO weaponry. The difference wasn't large in most cases, and was often limited to ammunition casings, although larger weapons such as main battle tank guns had larger bores. This had the effect of allowing them to use captured NATO ammunition in their weapons with the addition of a simple adapter sleeve or sabot (the latter used for tank and artillery rounds), but prevented NATO from capturing and using any Warsaw Pact ammunition.
Hitler would have loved to have invoked this trope further than the Nazis already did, particularly with the Maus heavy panzer and the ridiculously large Ratte, which really can't be described as anything other than a battleship on wheels. The armaments minister Albert Speer realized how impractical they were and strangled the ideas in the cradle.
The Landkreuzer P. 1500 Monster! A tank so big, it was designed to be submersible, not for naval warfare, but because it was too heavy to take bridges, so had to go straight through any rivers it came across.
Cuckoos. They lay their eggs in other birds' nests, and their chicks are so large, they monopolize the parents' attention and food supply.
It helps that as soon as the cuckoo chick hatches, it kicks the other eggs out of the nest so that it's the only one remaining.
Computer components are going this way. Take graphics cards for example: at first, all graphics cards took up a single expansion slot, and barely extended beyond the socket. Today, dual-slot coolers are the norm (due to the increase in heat put out,) and the highest-end cards can be over ten inches longs (27cm seems to be the norm for these long cards), while an ATX motherboard is about 9.5 inches wide. And triple-slot coolers are becoming popular.
CPU coolers, as well. They can be so large as to not fit in particularly narrow cases.
If you've been tinkering with computers for a while, you can see how heatsinks have grown over the years from being completely absent on a 486DX, through a little one 4cm wide on on the 200MHz Pentium MMX, to great big hulking huge 10cm ones, to hulking huge ones with heat pipes...
Motherboards, too. The crowing example would be EVGA's Classified SR-2, a dual socket monster that uses its own form factor, and can only fit in a handful of cases on the market without major modifications.
Australia seems rather fond of big things as tourism landmarks, such as the Big Banana in Coffs Harbour. On Pitch segment on The Gruen Transfer had the winning ad use such big landmarks as cooling towers on nuclear reactors to try and sell nuclear power to Aussies.
Justified in the case of many animals that seek out the biggest available mates, as a large potential partner is probably older than a small one. If a big mate lived long enough to get big, while eating well enough to grow a massive body, then it's probably got better genes to contribute than some dinky youngster.
Also played straight with trees. If one tree in a forest is bigger, it casts a shadow over the ones surrounding it. They, in turn, grow bigger, therefore casting their own shadows, and so on. Bigger is therefore the only way to get full access to light.
Telescopes, professional and amateur. The bigger the main lens or mirror, the more light the telescope lets in, the fainter it can see; this trope absolutely applies. In 1789, Herschel constructed a telescope with a main mirror 4 feet wide, in a tube 40 feet long, supported on a huge scaffold frame. It was the world's largest for half a century, until Irishman William Parsons built one with a 6-foot main mirror (weighing three TONS), held up by stone walls looking straight of a medieval castle. In 1917, American Hale trumped that with a telescope main mirror of over 8 feet. Currently the world's largest telescope has a primary mirror over THIRTY-FOUR FEET across, large enough to park a bus on.
For amateur telescopes, in the mid 20th century 8 inches was considered fairly large. Now 16-inch telescopes are not uncommon, and there are some as large as 50 inches available to the wealthy amateur astronomer, so big you need to stand on a ladder to look through the eyepiece.
And then there's the RB-16, a pair of binoculars where EACH SIDE is 16 inches across. (And you look through them backwards, facing the opposite way to the view you see.)
Battleships back when they were still the naval state of the art. Justified in that bigger guns could (and still technically can) wreak more havoc over longer ranges than smaller ones given the advances in fire control at the time that made taking full advantage of said ranges actually feasible, but to carry said bigger guns you first of all needed a bigger ship.