Well... In one campaign we were trying to find a map to a certain place. However, because of our elf wizard's stubborness, they set fire to an altar for a god that the goblins who were living in the castle worshipped. Then, when we find the person with the map, we realize the fire has spread. When they throw the map into the fire, I go after it, but the elf trys to stop me and attempts to drag me out of the burning castle. I am so obsessed with the map that I go into combat with her and charge back after the map. Then, she realizes she can cast mage hand, leaving me stuck in the middle of a flaming circle of ground. Then, when we realized the map had caught fire, she tryed to put it out. When she rolled a 9, our DM said

"You pee on the map, putting the fire out."

It was so funny!!!!!

Thoruk, the barbarian, was in a party tasked with clearing kobolds out of a pair of dwarf brothers house. Thoruk wasn't really listening, so I ask a party member what we're doing, and they say "go in there and kill everything".

So, a few rooms in and Thoruk is at the front of the melee, leading the way into the house (it's a cave system but a comfy one). I am faced with 2 doors and am raging, so I roll randomly to see which I go through, and apparently it's a shrine, and there's no kobolds here. I say "I attack whatever's closest and then go back into the corridor" - thinking I would be smashing a chair but oh no, the DM describes how Thoruk raises his sword high and brings it crashing down onto the alter. roll a strength check, thoruk! (he plans on me going flying backwards like gimli in lord of the rings). Nat 20. Ok, Thoruk powers through and cracks the alter in half. All the magic users sense something powerful and very angry stirring in the room.

At this point some players are actually running from the house. Thoruk is entirely ignorant of magic so continues his attempts to kill the kobolds. Behind him, an ethereal figure of a dwarf woman appears. She stops Thoruk, and asks him just what he thinks he's doing. Thoruk replies, having seen her beard: "Stay back sir, there could be more of them", before charging on into the house.

Eventually the kobolds are dead and the Dwarven Goddess of Homely Protection has managed to corner Thoruk for a talking to about why he smashed her alter in half. Thoruk explains that he was asked to go in and destroy everything by the Brothers (whose house and alter this was). Dm says to roll deception, and I explain that Thoruk really believes what he says, so we agree to roll Persuasion (same modifier). Natural 20.

And that's how Thoruk convinced the Dwarven Goddess of Homely Protection that the dwarves who own the house asked him to come in and smash her alter.

Quote from ThorukDuckSlayer >>

Thoruk, the barbarian, was in a party tasked with clearing kobolds out of a pair of dwarf brothers house. Thoruk wasn't really listening, so I ask a party member what we're doing, and they say "go in there and kill everything".

So, a few rooms in and Thoruk is at the front of the melee, leading the way into the house (it's a cave system but a comfy one). I am faced with 2 doors and am raging, so I roll randomly to see which I go through, and apparently it's a shrine, and there's no kobolds here. I say "I attack whatever's closest and then go back into the corridor" - thinking I would be smashing a chair but oh no, the DM describes how Thoruk raises his sword high and brings it crashing down onto the alter. roll a strength check, thoruk! (he plans on me going flying backwards like gimli in lord of the rings). Nat 20. Ok, Thoruk powers through and cracks the alter in half. All the magic users sense something powerful and very angry stirring in the room.

At this point some players are actually running from the house. Thoruk is entirely ignorant of magic so continues his attempts to kill the kobolds. Behind him, an ethereal figure of a dwarf woman appears. She stops Thoruk, and asks him just what he thinks he's doing. Thoruk replies, having seen her beard: "Stay back sir, there could be more of them", before charging on into the house.

Eventually the kobolds are dead and the Dwarven Goddess of Homely Protection has managed to corner Thoruk for a talking to about why he smashed her alter in half. Thoruk explains that he was asked to go in and destroy everything by the Brothers (whose house and alter this was). Dm says to roll deception, and I explain that Thoruk really believes what he says, so we agree to roll Persuasion (same modifier). Natural 20.

And that's how Thoruk convinced the Dwarven Goddess of Homely Protection that the dwarves who own the house asked him to come in and smash her alter.

 That is so funny and amazing!

My 11th level Druid/Cleric who worshiped Rillifane Raliffil (the big tree god) got access to a 7th level spell slot with a weird magic thing and used it to create a tree temple. A bunch of sewer goblins came out and launched trebuchets of sewer stuff and killed my Druid who was in the nest at the top. She died. Then our Succubus bard revivified me. The tree temple disappeared because the Wizard wouldn’t let me renew it.

A character ate a delayed blast fireball... not realizing what it would do. One minute later, they exploded.

We had a great (small) group of players that really like to role-play.  2 fighters - my half-orc barbarian (Grumble) who was strong, stupid and smelly, and another players Paladin, who was our tank. we were in Expedition to the Barrier peaks and the paladin had picked up space armor that gave him a serious AC.  They tricked me into an automated shower, which had water jets and perfume dispensers flying all around me. Nope, nope, nope.  So, I grabbed one and yanked it out of the wall (I knew it was gonna hurt, my character didn't). Sparks fly and I take electrical damage.  Paladin is just laughing hysterically.  I walked up and announced to the DM I was gonna punch him. He said, "I deserve it".  I rolled a natural 20 and did double damage.  Knocked him unconscious and dented his helmet so it would no longer fit. Dropped his AC by 2 points. Laughed the rest of the campaign.

My halfling bard, Ozzy, who I'd decided to play as a kind of maverick weirdo (think Captain Jack Sparrow), did crazy stuff just for the sake of it. One time the group had just broken someone out of a dungeon and Ozzy decided to take the latrine bucket with him - just because. Luckily it came in useful during a combat, when Ozzy used the contents of the bucket as a weapon, throwing them in a guard's face, then putting the bucket on his head and kicking it after he had been made prone. 

Oh and recently in the Death House in CoS, my fighter, who's incredibly dumb but thinks he's really smart, only just managed to subdue the animate broom and lock it in the cupboard. On the way out, he decided to kick the door in anger at having taken damage from a broom. So the DM had him roll a strength check - of course it was a 19. So the door broke open...and out came the broom again. Luckily he managed to scarper out of the room before taking any more damage. 

I got double natural 20s at disadvantage for my character to take a leak on a tree stump. He was drunk. He broke it in half. Nat 20 on urination. Legendary. 

One of the characters in the game I dm has taken damage from cheese. Twice