While rule 1 and 2 in Minecraft are that you shouldn't respectively dig straight down or straight up, rule 3 is about not making fireplaces when there's a lot of wood nearby. Here's why:
This YouTube Video, where a user tries to explain how to make a fireplace and inadvertently burns down his whole house.
His video isn't the only one about that kind of incident either with about dozen of people making the same mistake. This person managed to burn down more than a house.
I was playing in a shared world owned by another player. My "friend" and I shared a house, and while I was away he poured lava onto the roof. The only sign of this was a block descending from the second floor ceiling, which he expected me to destroy out of curiosity, killing myself. I saw the block but ignored it. Minutes later, the lava burned through the roof while I was on the first floor, leading to the following exchange:
Me: Holy f—- the house is flooding with lava!
Cue uncontrollable laughter as I burn to death.
One guy, in revenge for having his mine flooded, sets up a trap where two people got trapped inside a prison, and the only way out was jumping off. Need we mention that this prison is about 9000 feet in the air?
On my friend's personal server, someone's obscenely large tower/home was defaced with a wool billboard saying "(X) HAS A BIG, FLOPPY VAGINA." This ended up being our facebook group's photo. (He was cool with it.)
The absolutely epic Troll Mojang pulled off with the April Fools Day prank; Minecraft 2.0, featuring sensitive chickens that don't like being looked at, Redstone Bugs(literal ones, not glitches), and a stab at the people who want realism in the game via torches not lasting forever. Sadly, the page containing the download was taken down on April 2nd.
Others
Minecraft hit one million sales. Drunk Notch, karaoke, and a nerf gun followed.
Another YouTube video, this time a recording of someone's live stream where he was just wrapping up for the session. The music just perfects the overall mood. WHAT THE SHIT-*dies*
An LPer by the name of bananapielord had uploaded his Minecraft world for his fans to edit as they please, and spent the next few videos showcasing the worlds they sent back. The third world in this video, showcased seven minutes in, has some interesting changes made to his house. Hilarity Ensues when he accidentally sets off a block of TNT.
The new Beta 1.2 update allows players to dye wool blocks different colors. The funny thing is that you can also do this to living sheep, resulting in a swarm of sheep in outlandish colorations.
Even better, when you shear the sheep, and the wool grows back, it's still the same color as the dye.
A hilarious glitch that makes you move super fast when the time is moved forward to compensate for how long it's "been." You have to see it to understand.
These two adventurers at the 14:00 point, find out that they don't make it in home in time, so they both build makeshift shelters, leading to a funny Inaction Sequence where they discover that one player lacks cobblestone to smelt glass in a furnace and the other finds out that he lacks sand so he can't make glass either. They find their own solutions to see outside. After a daybreak, they visit each other's "houses".
"Chickens fucking everywhere!". Someone finds out the properties of eggs when thrown at stuff (ie, they can spawn 1-4 chickens), so he and a bunch of friends mess with it, but they soon realise they've woken a sleeping giant here. Eventually the server overloads, especially when he tries something drastic.
This entire video. Filled with plenty of Angrish, pained cries of "WHAT THE FRICK", and failed attempts to ride a minecart, this stream has something for everyone!
Most items that involve the day/night cycle or direction start to bug out when you enter the Nether. However, the silliest case of this would have to be wood-and-wool beds exploding violently when one attempts to use them.
The Beta 1.6.6 patch notes. It has some nice tweaks, nothing too major... Wait, "Removed Herobrine"? What.
That's been in every patch for some time. Either Notch still thinks it's hilarious, or he's trying to do damage control on the persistence of the meme.
for those curious, the suit ended in not only a refusal, but notch won with the court ruleing that "scrolls" was not likely to be mistaken for the full title of which the lawsuit was over.
It is now possible, in creative, to latch onto animals with a fishing rod, fly up to a very great height and yank them, thus causing them to go flying for miles. It never gets old.
Monster Spawners usually only create boring zombies or skeletons, but through hacking, you can get anything from pigs to Endermen. Hilarity is sure to ensue.
Heck, the entirety of "Enderman Roomate", especially "What the-".
Parts 31, 32, and 33 of his Minecraft videos are a textbook example of From Bad to Worse. in Part 31, Toby drowns in the water near his house when he forgets to surface for air. Then, because his bed was obstructed, he doesn't respawn in his house and has to find where he died, a problem made worse by his No Sense of Direction. In Part 32, Toby is forced to turn the game to peaceful mode as he dives for his items. Having spent half the video looking for his items, he goes off to bed... and dies because it was obstructed, losing his items and being teleported away from his house again. Part 33 is entirely comprised of him trying to find his house.
Someone made fun of the broken base, FOR EVERY UPDATE UP TO THE HALLOWEEN UPDATE! Link: Mojang goes bankrupt.
These SMP players tried to grief a griefer by encasing his house in a glass sphere and filling it with lava. Then it began to leak, and what results could be a scene from a typical disaster movie.
"We've created the Sun."
"IT'S LEAKING!"
The 1.1 update added multiple language options. Guess what one of the options is? Pirate!
A chunks error can cause this◊ to happen. That player won't be running out of beef any time soon.
Version 1.2 introduces something that Creepers are afraid of: Cats. No, really. Tame a few and watch Creepers avoid you like the plague.
The code when enchanting, when translated, is completely random and nonsensical. What the nether is "shorten wet beast physical?"
Heck, ANY Game Chap mod review, especially the Herobrine series.
Team Avolition, a griefing team, was challenged to see how much griefing they could perform on the Doridian server before getting caught. Stealing 3,500 diamonds, burning down the fabled city, and annoying the crud out of an admin who has no ban powers are the LEAST of their accomplishments. Doubles as a Crowning Moment of Awesome that they were able to pull this off in the first place.
Their jihad against the Rice-Think server was also glorious. The owner and his moderators started a smear campaign on both their website and Team AVO's forums, claiming that they had "won" and that they would "never be defeated." When their server went public, Team AVO found out that no attempt was made to hide or protect anything of value, and that the server's moderation team had the combined mental acuity of an acorn. Gather round and hear the tale of the dumbest admin who ever lived.
Now, Team Avolition has it's own trope page, right there.
"Sometimes it's hard to be a God", featuring the Clay Mod, full of Literal Metaphors (such as the world being named "The Heavens and the Earth"), faux-epic moments (such as green and blue soldiers parachuting in on feathers), and ultimately culminating in God just deciding to delete "The Heavens and the Earth".
Rubber Ross's Derpcraft. What's even funnier is that the cartoon was based on his initial reactions.
Alekidsonic's Minecraft shorts. It's also a bit of a Take That to people who start playing Minecraft for the very first time.
The Weeping Angel mod, when spotlighted by the Yogscast, has one of the Angels going into Simon's house, and he doesn't have a pickaxe to destroy it with. How is this solved? By digging a hole in the floor, getting the Angel to fall into it... and just putting floor blocks over it. There's now a Weeping Angel trapped under the floorboards. Problem solved.
After 34 minutes of fail in the 404 challenge, these two adventurers decide to give it one last try and make a "pimp room". The result is...well, just watch.
On the Caznowl FFA, this troper used 22 lava buckets and a ton of cobblestone to wreck the sign above spawn. The result? One heckuva lava fall, and both this troper and his friend getting killed.
Also, every single pre-review intro for Mod Spotlights, especially the Weird Hybrids mod. Why does this guy not have a trope page yet? Let's Fix that. Sky Does Minecraft
The Mob Rap 2 has a few joke verses, which come from the Chicken and the Squid. Also, Skeleton's reaction to Herobrine showing up can be seen as this.
This video is probably the most cheerful death montage ever recorded. It showcases 50 noteworthy deaths from a player who is prone to maniacal laughter, blind panic, and general clumsiness all at once.