Mine would be in Fallout 3 when I hit a super mutant with a Gauss Rifle and launched the mutant like a hundred feet in the air. The mutant landed onto Fawkes and killed him. It was hilarious.

Mine would be in fallout 3 i shot a yao guia with a chinese assualt rifle and he launched so far he disappeared over the horizon

I once spawned a squad of NCR heavy troopers in the gate from Freeside to the Strip and watched chaos ensue.

Putting about 200+ mines in front of Alistar Tenpenny then shot him with a pistol and watched him become a rocket man.

I shot a rocket at a Super Mutant's feet. It proceeded to fly about 30 feet in the air while doing a 180-degree sideflip and lose its head in the process.

In the early versions of my Mass Effect mod, the alliance NPCs were based out of Megaton (they anticipated that Collectors would attack since so many people are there).  

I had a volus vendor with them who sold things to the player (thermal clip ammo, grenades, etc) from a little booth.  Since his area had a lot of cool things, I figured some players would try to steal from him.  So I decided to give him a ridiculously powerful shotgun - 16x the damage of a normal Fallout shotgun, fully automatic, 50% crit chance with knockdown, and custom projectiles that explode in a small radius with insane impact force.  

To test it, I ran up to his area and stole 2 things: he immediately pulled out the shotgun and blasted me.  The first shot crippled both my arms and wiped out about 90% of my health - the 2nd shot knocked me back, hundreds of feet through the air.  He continues firing, blowing off both my legs in midair and killing me.  

My legless body lands about a quarter of a mile outside Megaton in a bland, low detail area the player clearly wasn't meant to see.

It was just the most over-the-top, insane thing I had seen happen in the game... had me laughing so hard.

I am a bad man when it comes to funny stuff in Fallout because some they are XXXtreme with creme.Now to be very,very serious.I spawned four Brotherhood of steel members with Breeze body types and in then i spawned Easy Pete fully naked and when i mean fully naked its fuly naked and then i gave Pete a stripper pole and then he danced.The Brotherhood members for some reasons started to shoot at themselfes becasue their eyes were burning from Pete's dance but well it was pretty much like this.

Spoiler:

The funnies thing i made in Fallout? Hmmm I remember the badest thing i did. Once i have saved Red in germantown i gived her a Fatman bacause i was overloaded, shortly after we encoutered some mutants. I was only able to draw my gun and was lauched to the by nuke explosion. In the same moment i get the mesage that red have died and could see some mutans flying too.

At last i did a lot of funny things, bottlecapsmines, fatmans, teasing deathclaws with rusty pistols to the death. i don´t remmeber what of this was the best. Oh now i remeber i it was the Gendernator!
That gun switch the gender of all a NPCs! That was a lot of fun!

All i can say is poor rotface hahaha.

The first time in New Vegas' streets where a kid is chasing that huge rat screaming "We're gonna have dinner tonight!". I thought that was pretty funny.

And in fallout 3, where you have just recieved your bb gun, I once shot dad in the leg before Jonas took the picture and he shouted "What is WRONG WITH YOU?!". It's the simpler things for me

farlas816 wrote:

I once spawned a squad of NCR heavy troopers in the gate from Freeside to the Strip and watched chaos ensue.

I once spawned an army of NCR heavy troopers in the gate from Freeside to the Strip and watched my game crash

Though not really the funniest, I remember the first time I experienced the "flying Deathclaw glitch" in Fallout 3. (this was back when I played on Xbox 360) I took a shot at him with a sniper rifle and he became aware of me. Just as he turned toward me, WHOOOOOOOP! Up into the sky he went. I had never heard of the glitch before so I naturally was jaw-dropped mesmerized. This happened a several more times as he kept on respawning at ground level before ascending again. I went to get a closer look and then he respawned again right in my face, but this time he didn't start floating up into the sky. He promptly gave me a slap in the face and I was instantly dead. I then loaded a save I made during one of his ascensions and after it loaded, he immediately fell to his death. Problem solved.

My most memorable and IMHO funniest moment was meeting Harold
Hilarious dialogue and just plain damn fun to meet him, after playing the old games.
The second place goes to the collective dialogue from Wild Wasteland.

Accidentally closed a door on a companion and he proceeded to explode into a mess of glitchy limbs and followed me from underneath the map

when taking on driver nelphi, i used the 1st recon to help me since they are the best of the best bla bla bla, to take on the bounty. So heading to the sniping position, Gorobets stepped on every landmine along the way, breaking his leg. So, assuming that they know how their own bounties worked, I baited Nelphi out in the open, then I got shot by the marksmen. Second attempt, Lieutenant G. broke his legs again on the way to the sniper nest, and they blew Nelphi's head up. I decided to take him on on my own after that

Walking up to the deathclaw sanctuary as a level 13, and seeing no deathclaws until I decided to check behind me and was instantly shot 500 feet into the air, dying in the process.

I've never laughed so hard.

I was heading to the arlington library and while i was almost there, i stumbled into a ruined building with 2 raiders there. Nothing really special but the building was a literal trap-house (the building across the street from the library). The 2 raiders spotted me before i killed them and they decided to bomb rush me ( they were at the top floor). So by doing that, they set off all of their trip-wires, bear traps and mines. I lost sight of them but all i could hear was *boom*Boom*BOOM*. I laughed so hard i almost fell of my chair

zparkzter wrote:

I was heading to the arlington library and while i was almost there, i stumbled into a ruined building with 2 raiders there. Nothing really special but the building was a literal trap-house (the building across the street from the library). The 2 raiders spotted me before i killed them and they decided to bomb rush me ( they were at the top floor). So by doing that, they set off all of their trip-wires, bear traps and mines. I lost sight of them but all i could hear was *boom*Boom*BOOM*. I laughed so hard i almost fell of my chair

seems like something straight out of tom and jerry

One word...Fisto...I laughed so hard when I seen him...I found him like twice I was watching my aunt play fallout on Xbox then she found fisto and we both laughed so hard

I can't remember the exact details where or when this happened but I recall having my entire body lite up by explosions which resulted in my decapitation at such an intense velocity that it bounced around the walls of the halls like a god damn ping pong ball.
It was so jarring to me that I was rendered speechless for a few moments, soon later busting out laughing.