"Operation Final Rest". Resulted in TPK, naturally.
"Operation Fallen God". TPK, all Colonel level soldiers.
"Operation Hot Mother". No, really◊. Apparently Buster is the one at XCOM HQ coming up with all of the operation names. For bonus points that name was assigned to the "Gangplank" mission from the Slingshot DLC.
"Operation Fallen Serpent". Council mission. x12 Thin Men corpses.
"Operation Evil Alien". Gee, you think?
"Operation Blind Man". Even worse if you're hit with some of the worst cases of Artificial Stupidity the game had to offer.
"Operation Black Priest"
"Operation: Cryptic Line". Guess someone in Central is fan of meta jokes.
"Operation Twisted Hero". Becomes worse if your rising star is critically injured and then mind controlled into killing their teammates.
"Operation Empty Grave." Don't worry, only 3 soldiers were killed that mission.
"Operation Sacred Empire". Better if the target is a UFO interceptors splashed in Japan.
"Operation Spectral Sentinel". Terror mission with all troopers equipped with Ghost Armor.
"Operation Final Breath". Well, maybe for the aliens and any rookie unlucky enough to not dodge a shot.
"Operation Constant Paramour" for Site Recon. Apparently being a Chrysallid hive counts as cheating.
"Operation Lazy Justice". Code Black on an Abduction mission.
"Operation Brutal Fall". During a typical "Overwatch spree", a floater flew straight into the fray. It was shot the moment it appeared and was tossed across the map.
"Operation Fallen Saviour". And....... There goes my support, well good luck surviving the night everyone
"Operation Final Night". There goes my PSI trooper...
"Operation Final Fist." Featuring four EXALT taken out by the MEC Trooper's rocket fist, including the last!
The reactions your troopers have to getting Mind Controlled can fit in here.
Killing a Floater through Overwatch when they are just starting to move. Since they move around by using the thrusters built into their body, the corpse will hurtle across the map until it hits the invisible wall at the map edge. Extra hilarious if they were going up... they never come back down!
Blasting Floaters out of the sky with rockets really never gets old, especially with several bunched together.
On a related note, once in a while Mutons will ragdoll and convulse in a blackly amusing fashion when you put them down, especially in Terror Mission maps. They just flop there and wobble so much.
The same thing can happen with Cyberdisks and other flying enemies in certain maps with 'bottomless pits' (such as the Alien Base, the Skyscraper Rooftop, or a Battleship). The corpse or wreckage will fall off the map, camera in tow... and then the camera has to hurriedly pan back to the action when the corpse/wreck is deleted.
Ragdoll effects reach their full hilarity once the Alloy Cannon is researched. Imagine a Berserker charging one of your team mates only to be sent backflipping over a dumpster by a nearby assault class. It never stops being funny.
Use stealth to discover a group of Floaters without triggering them, then have your heavy "blind" fire a rocket into the middle. Their bodies will ragdoll in different directions to the very borders of the map.
The Ragdoll effects that ensue from Mec Trooper punches, especially ones that send the hapless victim through walls, are very satisfying and a joy to behold.
Muton Berserkers sometimes wig out and run back and forth - if the squad is prepared this can lead to a hilarious Humiliation Conga as the Berserker trips Overwatch shot after Overwatch shot. Bonus points if some of that Overwatch is from Sentinel-classed Supports.
Some players have taken to just luring the Berserker from one soldier to another, going round and round, until it dies.
Sometimes, it just takes one. With a reasonably powerful enough weapon, an Assault can Rapid Fire a Berserker and hit twice, have it charge at him or her, only to trigger the Close Combat Specialist ability from that same Assault, ending with one dead Berserker.
Another way to deal with them is to move up all soldiers to close range and set them into Overwatch, and have the last soldier finally fire, triggering its movement and then the fire from every soldier in the squad at once. Just like dominoes, but with more lasers and blood.
Alternatively, anything that can fly simply makes fun of the poor Berserkers. Endlessly running at you, never to succeed. Almost makes you feel bad for them. Almost.
Buildings can remain standing even if only a single wall tile remains. Try staying straight faced while that building in the middle of the graveyard is somehow standing with a single row of burnt bricks holding the entire building up as plasma fire is exchanged between the XCOM squad and a bunch of Thin Men.
It's exceptionally unlikely to happen, but non-explosive friendly fire does seem to exist in the game. Imagine - an Assault in low/half cover is outflanked by a Muton two tiles to his south-east, with a Berzerker standing directly next to him, to his north-west, directly opposite the other Muton. The Berserker has two hit points remaining from earlier attacks from the squad. The outflanking Muton raises its plasma rifle to attack - and you can't miss at that range, right? Wrong. It misses. The first shot goes wide, the second two shots smack straight into the Berzerker's face and kill it. Friendly Fire Isn't.
A Muton Elite throws a grenade at a nearby soldier, only to blow himself up. It was then finished off with another grenade.
The naming system can produce some funny moments: A rookie with the last name of Claus saved his team's asses thanks to his medkits. The kicker though, is that upon promotion, it turned out his given nickname was "Santa": "Santa" Claus is now a Colonel bringing 10hp restoring medkits to all the good soldiers each mission.
On a slightly different note, a sniper with the surname Walker. Open reaching Sergeant, the game promptly can give him the nickname...Walker.
Another example, a female sniper with the last name Kerrigan. Her handle once she reached Sergeant? Blades. To top it off, she turned out to be the only soldier to have psi-abilities in that playthrough.
Similarly, with Enemy Within, try getting a Sniper with the code-name of "Cyclops", especially if he's made the first recipient of mutagenic enhancements. Same goes for Tom Taylor if made a MEC trooper. "More power" indeed.
Colonel Sanders. Nickname: Chicken. That is all.
A MEC Trooper that helped out the troopers in a tight spot ends up earning the nickname "Big Daddy".
Also, making a soldier called Murphy into a MEC Trooper, who then proceeds to get the nickname "Robby".
One possible name for a Chinese Soldier is "Long Wang".
It's, ironically enough, possible with enough concentrated firepower to scare a chryssalid. The one trooper who accomplished this hit Sergeant after this mission, and was nicknamed "Scarecrow".
The first soldier who went through genetic augmentation in one playthrough had the first name "Jesus" (he was Mexican). His last name was Ramirez. So it's obvious he's capable of doing everything!
A Heavy specced for explosives spent all his missions causing massive property damage. Every time. The Random Generator happened to give him the nickname "Dozer".
Anytime an enemy appears and walks right into a Overwatch crossfire is always good for a laugh, especially when it happens to a tough/annoying enemy. They get a little intro then get shredded by an unholy amount of firepower. More Dakka is always the proper solution to your problems.
The Seekers introduce in Enemy Within cloak then move around the battlefield for a fortunate time to strike, decloaking to attack a unit. When they decloak overwatch is triggered. Imagine that there is just one left and you have all your troops clustered within Lo S with one another and on overwatch. The Seeker appears and is shredded by 5 instances of overwatch. Total damage was 31 points of damage on it. For reference, the Seeker has a max HP of 5 by default.
Such as the unfortunate Thin Man who spawned in atop a subway train car during Enemy Unknown's bomb mission and was promptly met by a hail of plasma bolts and an alloy cannon shot. His buddy landed seconds later a few tiles to the south and was promptly obliterated by a plasma sniper shot.
The only thing better than your whole team destroying an alien is a single soldier utterly decimating an alien. For example, during a Council mission, positioning a shotgun-toting Assault on a building that a Thin Man will always jump onto. When the Thin Man drops, activate Close Combat Specialist, and time slowed as he managed to get one foot on the roof before getting blown apart by a Scatter Laser.
EXALT troops sometimes do this as well. But they also come from different directions, which can work well, but might also lead to each EXALT soldier tripping a different Overwatch, resulting in the entire wave getting wiped out.
EXALT troops also enter the battlefield from the edges of the map, but they actually appear off the map and run in, either climbing over walls or running in from Behind the Black. This is still considered movement, which means it still triggers Overwatch, even when they're no immediately visible, which can lead to moments where a sniper on Overwatch will actually spot and kill EXALT agents before they step onto the map.
Alloy SHIVs can provide cover - for your soldiers but ALSO for the aliens. They often run up to hide behind the war machine they're supposed to be shooting at instead. Doubly hilarious if you react by just driving the SHIV away, leaving the alien out in the open and probably feeling like a massive idiot.
Double bonus; park the SHIV a couple tiles away and ANNIHILATE the alien just using it as cover. The irony...
Or any time a soldier or alien decides to randomly smash a window when they don't need to. For example, smashing a skylight they happen to be hiding near to shoot at an enemy on the same roof, sometimes just a few feet away.
There are many ways a Soldier's aim can be reduced to paltry levels in the field. It always seems something out of a military farce film when the Rookie runs up to a weakened Muton, fires at point blank range yet only managing to destroy the wall right behind it, and then being cut down by the bewildered alien.
What can be especially hilarious is having multiple heavies and other troops all go into Overwatch, and watch an alien jump out and trigger an entire squad, who unleash a massive torrent of bullets, lasers, or plasma that pours into the alien...and every shot misses.
Or, alternatively, having all those Heavies miss completely, only to hear towards the very end a single bullet, laser beam or plasma bolt streak through the air and kill the enemy as your sniper scores the kill.
OR have every single one of your soldiers miss...only to have the Floater soar right into the face of your Assault. Close Combat Specialist.
Taking advantage of the game's aiming mechanics can lead to some oddly funny moments. Like if a soldier has been heavily wounded while the Second Wave option Red Fog is turned on (which reduces their accuracy) and has an equally wounded enemy up close. You might have a 23% shot of hitting him with that plasma rifle, but that arc thrower has a 98% chance of success. Ride the lightning, baby!
Occasionally, missed shots actually hit the target visually, but have no effect, prompting loud, angry claims of bullshit from players and sometimes the soldier who fired the shot as well.
On the flipside, plasma shots will at times go straight passed their intended target, only for the target's head to briefly glow green anyway when the game decides to count it as a hit.
Unfortunately for Sectopods, they're not immune to the splash damage from their own weapons. A Sectopod taking on, for example, a mind-controlled Berserker at near point-blank range might wind up causing more damage to itself than the Berserker would have, possibly even killing itself if it took enough damage beforehand.
Once more with the ragdoll physics - punching an Ethereal to death with the Kinetic Strike Module may be the funniest of them all. Normally, they wear long, fancy robes. When they go flying, though, the robes go head-over-heels, making it look like nothing so much as a very proper lady whose dress has undergone a serious wardrobe malfunction.
The KSM is made for things like this - it's Black Comedy, yes, but when a particularly annoying EXALT agent or Sectoid has evaded all the fire you've aimed at it, there's little that's quite so hilarious as stomping a MEC up to it and punching it through a wall or into a car so hard that it explodes.
Punching it through a car...that explodes...and kills the three enemies behind it, ending the mission.
An interesting note about EXALT's AI is that they are suicidally determined to reach their objective at any cost without any regard to their own safety. This means that placing a MEC with the kinetic strike module in an area that EXALT wants to capture results in a lot of them being sent through nearby walls.
Occasionally a visual glitch can cause the projectile and the weaponry to wind up not remotely aligned. Hilarity ensues as the gun is aimed parralel to the window - and projectiles shoot out of the side and score a lethal hit!
Outclassed enemies will sometimes fall back. This can lead to situations like Strike One bursting in on a UFO's Ethereal and its Elite Muton bodyguard, whereupon the would-be Praetorian promptly appears to decide it's not getting paid enough for this, and attempts to flee out the back door, leaving its master to be blown to pieces.
The final mission cutscene. In the rare event that every soldier except for the crucial volunteer dies in the final mission you will be treated to the same cutscene as normal... With the volunteer telling NOBODY to leave them. The camera tracks as if there are still characters in their normal place and the volunteer even does the animation to push the others out with psy power. It's just that there is nobody there to be pushed. Makes a dramatic ending seem quite silly.
Dr. Shen's entry in the XCOM Database, which is of course narrated by the base's AI:
Dr. Raymond Shen is the Chief Engineer of the XCOM Project. Dr. Shen has proven to be an invaluable asset with his decades of experience. The XCOM project is lucky to have such a brilliant, dedicated, world renowned, award winning engineer at its disposal. Please note: This artificial intelligence was created by Dr. Shen.
Enemy Unknown's "enemies appear from nowhere" can, very rarely, go absolutely haywire. It's one thing having a trio of sectoids appear in the middle of your troops—it's another for every single enemy in a supply ship to teleport in sequence into firing range. That's including at least two sectopods in addition to about two dozen other enemies of various species. At least in my case the game crashed in the middle of the first round following the mass spawning, so alas no seeing if both heavies emptying rockets into the crowd would've saved the team.
Keep zapping aliens unconscious for multiple missions without an alien containment and watch how increasingly annoyed and verbose the good doctor gets after each mission.