"This cult of special forces is as sensible as to form a Royal Corps of Tree Climbers and say that no soldier who does not wear its green hat with a bunch of oak leaves stuck in it should be expected to climb a tree"
— Field Marshal Slim
Military fiction will generally focus on units considered elite in some fashion, even if it is obvious that the regular units found in the same battle are just as much in the thick of it.
This is particularly common in fiction set in World War II: If it is a US unit that is in focus, it is more likely to be Airborne, Marine Corps or Rangers than standard Army. British units are more likely to be SAS or Paras, though curiously enough rarely Royal Marines, SBS or even the vaunted Commando raiders. Soviets are more likely to be Guards than regular. Germans in this era are more likely to be Waffen-SS with camouflage uniforms; even in late-war scenarios where German territory is being invaded you are more likely to face proper infantry with decent weapons and gear rather than teenage and elderly Volkssturm troops armed with crude "emergency weapons" or older captured stuff.
Presumably happens because of the Rule Of Cool: famous units and battles are simply more "special". Also, since special forces units consists of better trained soldiers with high qualifications and (usually) superior equipments, it's generally more believable for them to succeed. For works based on Real Life, this focus can simply reflect historical Truth in Television, as is the case with Black Hawk Down and Band of Brothers. Insofar as elite forces have a smaller average unit size and this is a desirable situation in a fictional work, that's another reason for this trope.
Interestingly, the writers often have no idea what the unit designations actually refer to. "Army Ranger," "Navy SEALs," "Special Forces," and "Green Berets" are all conflated into generic commandos (most often referred to as 'operators' or 'shooters') with overlapping roles. Of course there is a certain amount of overlap, but in general terms these kinds of units are divided into two camps: Elite regular formations (Rangers and Royal Marines for example) who are highly trained regular soldiers; and Special Forces (SEALS, Green Berets, SAS etc) who operate in small teams and are brought in for specific missions.
The same is applicable to entire branches of the armed forces: in past, chariots were more glamorous than everyone else, then cavalry, especially heavy knights, hussars and cuirassiers. With the introduction of aerial warfare, the saddle of glory promptly turned into fighter pilot's seat.
For when the elites of society are more glamorous, see The Beautiful Elite.
Section 9 in Ghost in the Shell could be seen as an elite counter-terror police unit (the name itself is speculated to be a homage to the GSG-9). When top-ranking government officials involved in the conspiracy wants them neutralized, they have to send the JMSDF's Umibozu commandos to covertly kill them.
All the named and important characters that are shown fighting in Code Geass are elite soldiers of some kind. The Black Knights consists of the Zero Squad, led by Ace Pilot Kallen, the Four Holy Swords, led by Todoh, and former resistance members who've been promoted due to seniority. Britannia, meanwhile, has the bulk of its military power seemingly consisting of Suzaku and the Lancelot, Cornelia and her Glaston Knights, Schneizel's faction and his cool toys, and the Knights of Rounds. Regular soldiers are usually just cannon-fodder, unless they're used for an important strategic plot. Even the China arc focuses mainly on Li Xingke and those loyal to him.
In Rose of Versailles the military units that receive the most screentime are literally the elite of the elite: the Garde du Corps du Roi is the elite regiment of the French cavalry and Oscar serves in their first company (that is considered even more elite than the rest of the regiment), and in the French Guards (the elite regiment of the French Army: they may be infantry, but they're considered more prestigious than any cavalry due being a Badass Army) she commanded a grenatier company (grenatiers being infantry), identified as such by the uniforms. Even the named units that received screentime are elite: the La Fere (manga only, thanks to Napoleon Bonaparte showing up to provide a Sequel Hook) had earned the fame as elite artillery (and taught recruits how to fire cannons), the Royal-Suédois (thanks to Fersen being their commander) was elite Swedish infantry, and the Royal Allemand (that got Worfed by the rebelling French Guards even when supported by an unidentified grenatier regiment) was elite German cavalry.
Justified by Oscar's father using his political clout to get her into the Garde du Corps, Marie Antoinette, upon receiving Oscar's request for a demotion, choosing specifically the French Guards due them being part of the Royal Household, Napoleon being just that good to be assigned to that regiment, and the foreign regiments being raised specifically to be elite troops and more loyal than non-Household French-raised regiments.
The Halo fan fiction The Life is practically built around this trope.
Extensively played with in The Universiad where some Originals are members of elite groups and others are not. In fact, at least one group, the Close Air/Orbital Support Task Force, explicitly takes pride in being the regular joe schmoes who unglamorously play A-10 INSPACE.
Heartbreak Ridge. Few marines fought at the Battle of Heartbreak Ridge, so the backstory of Clint Eastwood's character was changed to having first served in the 2nd Infantry Division in Korea, and joining the USMC afterwards. However it was the US Army Rangers who rescued American medical students in Grenada, not the Recon marines as portrayed in the film.
Apocalypse Now follows the journey of Captain Willard (505th of 173rd Airborne Brigade and assigned to MACV-SOG, a classified United States Special Operations Forces unit which conducted ops in Vietnam) on a military-sanctioned assassination mission (and not his first). He does depend on a group of enlisted Navy sailors to get the job done however, and is escorted up the Nung River by Colonel Kilgore of the 1st Squadron of the 9th Air Cavalry.
In Sergey Bondarchuk's Waterloo a disproportionate amount of screen time is devoted to the Polish Lancers of the Imperial Guard, who in actual fact were just one squadron strong in 1815 and thus much too small a unit to make a significant contribution. In the film it is they who throw back the charge of the Union Brigade (Royal Dragoons, Royal Scots Greys and Inniskillin Dragoons), in actual fact it was two regiments of French line lancers, who wore a very different uniform (green jackets, brass helmets). Also not untypically the only British cavalry regiment shown in that charge is the Scots Greys, who were the only dragoons one to wear bearskin caps instead of helmets.
The Squad in the Doom film is made out to be an elite team, which was not the case in the game itself. Them being military regulars rather than elites would actually have helped the plot, as it would have made the presence of Portman and The Kid (both of whom had absolutely no business being in an elite military squad)at least somewhat less egregious.
Top Gun follows a squadron of navy aviators through their training in the prestigious "Top Gun" elite school for aerial combat. The real TOPGUN (and its Air Force equivalent, Red Flag) is more along the lines of "learn this shit, then go teach it to your home squadron."
Partially averted in Three Kings. Though Major Gates is a former Delta operator and a Special Forces/Ranger qualified Soldier, the warriors he leads are simple Civil Affairs Soldiers.
Black Hawk Down follows a significant portion of Task Force Ranger, which is made of several Ranger companies as well as a squadron of Delta Force operators.
Averted in Dog Soldiers — an SAS squad are discovered dead at the start of the film, and serve as a sort of off-screen Sacrificial Lion. The rest of the film focuses on regular troops.
The Sharpe books by Bernard Cornwell are focused on a small group of skirmisher riflemen, and quite often portray them as highly superior to regular rank-and-file infantrymen of the British Army who are hardly able to achieve anything without the help of the protagonists.
Even before they became Ragtag Bunchof Misfits, Sharpe's men belonged to the 95th Rifles (previously Prince Consort's Own), a reconnaissance unit using skirmisher tactics, camouflage and advanced weaponry, the closest thing to special forces in the Napoleonic Era.
In his political treatise The Prince, Niccolo Machiavelli complains bitterly about the Italian system of relying on mercenaries for war. One of his specific criticisms was that your average Italian mercenary group was almost entirely cavalry, because mounted soldiers were perceived as more elite. The fact that they could charge more for cavalry probably helped too.
While Navy SEAL Chris Kyle's autobiography American Sniper is an example, it contains an example too. He writes glowingly about "The Elite Elite" of the SEALs, the famed SEAL Team Six.
Live Action TV
In a Speculative Fiction example, most Star Trek series (and all the movies) follow a ship (always named Enterprise or USS Enterprise) that is often referred to as the "flagship of Starfleet" or "the best in the fleet". Those that didn't either followed one of the most strategically positioned bases in the Galaxy (Deep Space Nine), or a brand-spanking-new ship that is often referred to as one of the most advanced ships in the fleet (Star Trek: Voyager).
Even in situations where the Enterprise is neither the flagship nor the most technically-superior ship in the fleet, it has always the best crew by far.
The Deep Space Nine episode "Valiant" centers around the "Red Squad" elite cadets of Starfleet Academy. Of course, they're still cadets...it ends really badly.
Band Of Brothers covers the story of Easy Company of the 506th Regiment of the 101st Airborne.
In Warhammer 40000, Space Marines get most of the glory for any battle that they participate in, while the Imperial Guard really does most of the actual fighting; if the Space Marines were the tip of the spear of the Imperial military, the Imperial Guard would be the rest of the spear head, the shaft, and the person holding it. This is mostly because of the fact that Games Workshop has a crush on the Space Marines when it isn't putting them through The Worf Effect, though. Literally every second army released is some form of Space Marine army with its own special rules.
Somewhat justified, Space Marines are central to their religion. Plus, there are so few of them that there is ALWAYS a more important target they need to get to.
On the other hand, the Imperial Guard get the bestbooks. And this actually happens in-universe with the Guard's Stormtroopers (little relation) who get mocked by the grunts as 'toy soldiers' and 'glory boys'. And the Imperial Guard has plenty of fans, subverting this trope - the Space Marines are superhumans with training and equipment the Imperial Guard will never compare to, with enemies just as or even more dangerous. Regardless, the Imperial Guard fight those same enemies. Even so, it's not uncommon, in the books, for a tiny number of Marines to accomplish what a quarter million guardsmen couldn't, as in Dan Abnett's Brothers Of The Snake, in which six squads (60 Marines) capture a city that 300,000 guardsmen couldn't take. Then again, the Marines in question are Iron Snakes, one of the Marine chapters least inundated with the general Space Marine Proud Warrior Race Guy culture that tends get tons of them killed in pointless last stands and sends them straight into the teeth of massively superior forces.
Although the Storm Troopers recently got a massive boost - AP3 hellguns that tear through Chaos Marines like a knife through butter, anyone? To be fair, the hellgun used to be crappy for an allegedly "elite" unit - Str 3, like a normal lasgun, with the "bonus" of AP5. To put that in perspective, that means that it had the ability to ignore the armour of incredibly basic mooks. You know, like most other guns in the game.
In the table top game, it's a good general rule that an army's elite units are more ornate and fancy than the rank and file. Elites usually have more grandiose fluff. Headquarters units tend to have more Bling of War than a convention of militant pimps and fluff that goes Up to Eleven. Compare the already superhuman rank and file tactical marine◊ with an elite veteran marine◊ and finally a captain◊. This same pattern holds for pretty much every army.
Played with for Dark Eldar Scourges, elite soldiers who paid a Haemonculus obscene amounts to graft wings onto their backs (plus adding extra chest muscles, hollowing bones, that sort of thing). They are presented as vain, preening, arrogant pansies who mostly hang out in the sky above Commoragh and don't do a lot, then the Codex goes on to explain that they can afford this because they're so badass that other Dark Eldar will pay them obscene amounts to show up and help out whenever there's a fight, so they don't have to do a lot to be obscenely rich.
Another 40K example (possible subversion/inversion): Chaos Raptors generally see themselves as elites and act as such; most other Chaos Marines see them as preening weaklings.
4Chan's fan-chapter the Galactic Partridges tend to swoop in, make the last blow on the enemy, and take the credit from the people who actually did the work. They even spy on other chapters so they can better know when to take the credit. They have special drop pod that release a cloud of doves, John Woo style, in order to make more dramatic entrances. They are more of a parody of "elite" teams than anything else.
Invoked by At-43's faction the UNA, whose army's motto is "Better is Better".
Most RPGs in general have this effect, given that adventurers are almost universally above average.
In The World Of Darkness games, you will almost always be able to easily create a new character who is an elite member of modern society even if they are just a new member of their supernatural society. They will generally be one of The Beautiful Elite or this trope. This tends to make sense as either the character's latent supernatural powers aided them or their elite status was what attracted the supernatural to them. Starting characters can easily be world famous pro athletes, gifted, acclaimed scientists, or commandos in the modern world.
Star Wars RPGs will always have a great number of Jedi player characters if they are allowed.
The new editions of Paranoia feature rules for high-clearance player characters. The action of the game revolves around the political scheming of the elite.
Dark Heresy casts you as the servant of the Inquisition, which should in the 40k Universe come with great power and authority. Rogue Trader moves you even higher up the totem pole, putting you in a role which would be analogous to being Hernan Cortez while everyone else is a muck-farming peasant. Deathwatch promotes you all the way to a Super Soldier who is an object of reverence to common people. In each case, your station is far beyond that of normal human beings.
The Call of Duty series of games is a particularly good example:
In the first game the various characters you play are in the 101st Airborne, 6th Airborne and SAS, and the 13th Guards Rifle Division.
In the second your characters are from the 13th Guards again, 7th Armoured "Desert Rats" (historically distinguished itself in North Africa) and US Army Rangers.
Modern Warfare (CoD 4) has your characters being in the USMC Force Recon and SAS. The SAS are conducting the special operations for which they are famous; the USMC Force Recon, however, are largely playing the role of much more standard Marines or even regular army, so, oddly enough, they are the out of place unit.
Modern Warfare 2 now gives us the U.S. Army Rangers, and the international special ops unit Task Force 141. Again, though, both are largely doing the correct missions for their sorts of units.
CoD World at War: Marine Raiders/1st Marine Division and 150th Rifle Division (Historically the formation whose soldiers raised the Soviet flag on the Reichstag). However, the 150th Rifle Division might not exactly be considered elite, but That Other Wiki states that the 3rd Shock Army they were in, all Shock Armies in fact, received more artillery and armour support than other armies in Russia.
In Modern Warfare 3, you play a large part of the game as Frost, member of the Delta Force squad "Metal"; as World War III has started, their missions are sometimes real special forces work and sometimes they are just called in to help for more conventional tasks. Also, Yuri, the other main playable character, is former Spetsnaz and Captain Price, as whom you play during the last mission, is former SAS and Task Force 141.
NPC allies also include other elites, such as the French GIGN, US Navy SEALs, and more British SAS.
Most of your allies in Call Of Duty Black Ops 2 are part of the U.S. Navy's SEAL Team Six, the elite of the already-elite Navy SEALs. Not only that, David Mason, the player character, commands said team.
In Star Wars Republic Commando you play as the leader of a squad of elite Commandos that are in turn part of a larger army of elite troopers. Literally making you the best of the best of the best.
In Halo you normally play as the Master Chief, a super-elite semi-secret armoured and surgically enhanced badass Spartan-II Super Soldier. In the second game, you play as the Arbiter, a member of an alien species colloquially called "Elites" (all of whom are physically a match for the aforementioned Spartan-IIs). He also happens to be a former Supreme Commander who earned his position through Ass Kicking Equals Authority and is continually sent on Suicide Missions to atone for not being able to stop the Chief in the previous game.
In the third game's co-op mode, players 3 and 4 get to play as two Elites from the Fleet of Retribution's Special Warfare Group; N'tho 'Sraom is the youngest member of his Special Operations unit, and Usze 'Taham is a highly distinguished Fleet Security Commando.
Halo 3 ODST, the "gaiden" game of the series where you get to play as a regular human instead of a Spartan Super Soldier, still has you take the role of an elite ODST (the UNSC equivalent of Force Recon) sent in by Naval Intelligence, rather than a basic marine.
Halo Reach, maintains the tradition, as well. For one thing, NOBLE Team is fairly elite for a traditionally expendable Spartan-III team, to the point that one of their members is a much more valuable Spartan-II soldier. For another, the player character, Noble 6, is a black ops assassin who is the only other person with the same lethality rating as Master Chief, which is more impressive given that Noble 6 is also a Spartan-III.
Halo 4 continues the tradition, with Spartan-IVs as the stars of both the multiplayer and "Spartan Ops" co-op campaign.
Geist begins with the main character as a member of a suspicious paramilitary unit.
In Rise of Nations, the main infantry unit for the Americans is the Marine. This appears in a slightly different form elsewhere. As unique units of civilizations are upgraded past their historical ages, the game usually "elites" them. Sometimes, it's not so bad like companion cavalry -> cataphracts. Some are pushing it like Roman legions -> Praetorian Guard. But Hwarang -> Elite Hwarang -> Royal Hwarang -> Elite Royal Hwarang is just silly.
In Civilization 4, the unique unit for America is the Navy SEAL. (Which, in-game, is mechanically a buffed version of the Marine.)
Averted in the beginning of Valkyria Chronicles where your unit is made up out of a bunch of civilian militia recruits and local police forces with the only exceptional item being your main characters father's tank. However not only do your units gain 'elite' status when leveled high enough, by the end of the game your unit is taking on all the truly epic missions anyway. Hell, Squad 7 is the only reason Gallia doesn't fall. The entire army— the entire main army— gets completely obliterated in one mission. Absolutely nothing changes, because the army was useless anyway and their general was specifically sending your squad out to die as cannon fodder; Squad 7 was just too awesome to die. They might not have been officially named elites, but that's the only reason they weren't.
Medal of Honor: Allied Assault, MOHAA Spearhead and MOHAA Breakthrough.
The relaunch specifically noted that you were playing as Tier 1 operators (the elite of the elite of special forces). For the short period of time when you're not, you're still playing as Army Rangers, which are the elite of the Army.
The Americans at your disposal in Command And Conquer: Generals is made up of mostly elites and high-tech regulars. The Army Rangers are the basic U.S. Army infantry.
Partially averted in Operation Flashpoint: Dragon Rising. While there are plenty of missions where you play as a Force Recon unit named Saber, performing stealth and infiltration tasks...most of the really epic battles in the game have you in the role of a unit of standard frontline infantry named Dagger. And they're who you play as in the final, war-winning mission of the game.
In the original Operation Flashpoint, you play as four different people. One is an SF operator, yes, and playing as him involves frankly hair-raising crawls through enemy camps to sabotage tanks, and so forth. But the others are: a Pilot, flying a variety of missions which though important are nothing elite; a tank commander on the front line; and an infantryman in the thick of the fighting as part of a large unit with no special tasking or characteristics. So a massive aversion for the most part here. Spiritual SuccessorARMA and its sequel carry on in the same vein; the final DLC for Arm A II lets you play as an ordinary line infantryman, helicopter pilot or tank commander in the Army of the Czech Republic, who haven't even invaded anyone by themselves recently.
Additionally, missions featuring special forces operative are usually stealth-based and include very little to no actual fighting.
Rainbow Six comprises the Elites of the Elites. It's a multinational unit comprised of the best soldiers from each nation's commando teams.
The SWAT series; it's right there in the title really. Though in this case the franchise is actually a spin-off of the Police Quest games, which are a complete aversion.
Hilariously averted in Bad Company, where the cast is part of the Redshirt Army and knows it, once lampshading that they're going into an important but dangerous mission first just to see how dangerous it is, because the elites cost more money to train and are thus "too expensive to waste." Subverted in Bad Company 2 when Sweetwater insists the squad be the ones to tackle the villain's scheme, not trusting the spec-ops guys and their "pussy-assheartbeat monitors" to get the job done. The boys of B-Company succeed.
Shepard of Mass Effect starts out as top-tier Special Forces (indicated by the "N7" logo) before joining the Citadel's Spectre program. The program is so elite that merely being selected, even if one washes out, is good for one's career. The Spectres themselves are so elite that they are legally allowed to ignore laws.
The multiplayer mode in Mass Effect 3 centers around a squad of elite operatives with access to abilities and equipment comparable to Shepard's. The Illusive Man's Dragon Kai Leng was, like Shepard, an N7 operative.
In the Crusader games, you are already one of the most elite soldiers in the world...and then you defect and join the underfunded, undermanned, underequipped, undertrained Resistance and single-handedly take on missions it would normally take entire assault teams of rebels to complete.
The protagonist duo of the Army Of Two series began their careers as US Army Rangers who decided to become private military contractors (which tend to be Elites who get paid more and don't have to worry about a government defense budget and NATO "lowest bidder" equipment standardization).
Star Wars: The Old Republic has the Trooper character, the newest addition to the Republic's elite Havoc Squad, with a starting rank of Sergeant, and regarded as the 'best of the best'. Subverted, though, in that their starting equipment is a t-shirt and weapons worse than the rest of his squad and piddling starter weapons that are worse than the Separatists they'll be fighting, their own squadmates in Havoc, and even the local militia.
The two protagonists of Resident Evil were both elites in their previous careers (Jill was Delta Force and Chris was a USAF Fighter Pilot), and in-game are members of S.T.A.R.S., itself an elite squad in the Raccoon Police Department.
Averted in the Gears of War series, where all the main characters are their world's equivalent of regular enlisted men who keep stumbling into critical situations. The Onyx Guard, the actual elite of the COG military, only appear a couple times in the expanded universe, and get utterly slaughtered every time they do.
The Commandos series is one of the rare example of fictional representation of the British Commandos.
The Metal Gear Solid series has one of its major characters Big Boss be a career veteran of the United States Military who was involved in various Special Forces. He served as a Green Beret for 10 years until he was recruited by the CIA to be part of a fictional group known as FOX. Later on he served in Vietnam doing the CIA's top secret black ops working such groups as MAC-V SOG and the Navy Seals. According to the fiction of the universe Big Boss was also the man that helped found the Delta Force and his own personal black ops organization under his command called FOXHOUND, a successor to FOX.
During World War II the so-called "Chindits" were British special forces who performed operations of great heroism and derring-do and was widely publicized... But they suffered such heavy casualties and were so expensive to supply and train that their effectiveness was questionable. Field Marshall William Slim was probably speaking of the Chindits when he made the page quote. The Chindits spent 1942 and 43 playing hide-and-seek behind the Japanese lines in Burma to little effect. Slim took over the 14th Army in late 1943 and turned the entire force into highly mobile light infantry. Over the next two years he kicked the Japanese entirely out of Burma; his key tactic was to let his units be surrounded and rely on airdropped supplies to outlast the enemy offensives. He taught the 14th not to rely on conventional supply lines and make frequent offensive patrols - he refused to let his men think the Japanese were superior jungle fighters. In 1945 Slim's army was, man for man, the toughest fighting force in the world.
It is precisely because of this trope that the US Marine Corps resisted adding Force Recon to the newly-created Special Operations Command (the fabled SOCOM). "There are no special Marines."
Saddam-era Iraq's elites were the Republican Guard on the ground. In the air, it was the Iraqi Air Force, considered one of the best-trained and best-equipped air forces in the Arab world. The bulk of the Iraqi military, however, were made up of largely conscripted forces that were held together almost completely by the intimidation of their commanding officers, whose morale tactics could best be compared to Commissars from Warhammer 40000. When both the Airforce and the Republican Guard fell apart, the bulk of Saddam's military simply surrendered en mass. Thus illustrating an often forgotten but important lesson: never focus on your elites to the detriment of the rest of your military.
Many raised around the US Navy are often surprised and eventually annoyed at how many people think the only ships in the Navy are Aircraft Carriers and battleships.
Speaking of the Navy, they had commandos dating back as far as World War II, who were involved in underwater demolitions and deep sea recovery. Then came the Navy Seals, then the Navy Special Warfare Development Group, then SEAL Team Six. Today, anything Navy or special forces related would, odds are, center on Team Six.