What is the MOST FUN encounter you've had in 5e? And least fun?

[Raphite1]

I'm DMing the first 5th Edition game I've ever participated in, and so far it seems to be going great. We're about 8 hours and two sessions in. To help guide my efforts in building a fun an engaging world for the players, what are your answers to these two questions:

1) What is the most fun encounter you've experienced in 5th Edition? Why was it fun?

2) What was the least fun encounter you've experienced in 5th Edition? Why was it not fun?

[Falcon X]

Our favorite times while doing Hoard of the Dragon Queen have been the side-quests. Some of my invention.
Such as in Episode 4, there is a crazy Lurker protecting some dragon eggs and the adventurers convinced it to help them if they showed it where the meat locker was.
Or a quick adventure down into some underground caves to retrieve an item.

These were fun because they drew laughter, even at the expense of realism. They were an escape from our campaign's deep and serious nature, which was often boring.

My recommendation would to make your games episodal. Have constant beginnings, middles, and ends to adventures so the people feel they are accomplishing something.
Have each night's intrigue focus around a single creature, item, or person rather than a smorgasbord of stuff or just mundane people.

[Bubzors]

The group I DM'ed just wrapped our campaign of a year and a half IRL. There were many memorable moments, but my favorite combat encounter was a demon boss fight.

The party traveled through a portal to a pocket dimension of the demon. He stood on a central platform under an energy shield of some sort. Surrounding him were two separate layers of of floating rock platforms rotating in opposite circular directions around the central platform. The party had to jump around from platform to platform to destroy glowing pylons that powered the shield. On each platform were different monsters.

It was really neat as I made the platforms out of Styrofoam and painted them. I would rotate them every round. The party ended up doing well despite having brought a newborn tie fling along with them (that is a whole other story). Turns out a raging barbarian with haste and boots of springing and striding can jump really far ha.

As for the least favorite encounter for me was another boss fight. I made a strong sorcerer with lair and legendary actions thinking he would be bad ass... the party silenced, counters pellet and dispelled him to death. He lasted like 3 rounds. Oh well learned my lesson. Never expect one enemy to do much when the party has time to prepare

[Inevitability]

When I was DMing, two of my players had gotten separated from the remaining party members and had to ally with a previous enemy (Cleric specializing in ice magic). After getting said enemy to raise a previous party member, all four of them set off on the back of the cleric's white dragon ally.

They then proceeded to backstab her. While on that dragon. The fight was hard for both sides, with the dragon only able to reach them with his tail and breath weapon, the cleric spending all her actions on healing, and the party members taking heavy damage, but in the end they brought their foes down, first the cleric and then the dragon.

That was when they realized something very important. This important thing being that only one party member was still standing, and the dragon was going to crash in a few seconds. The final survivor quickly brought his two friends back up and they flew away seconds before the dragon hit the ground.

When they looted the bodies afterwards, they asked if they could find the cleric's remains. My response was something akin to: 'The cleric got stabbed a dozen times, was caught by a breath weapon twice, as well as several of your area attacks, then fell down several hundred feet. You find nothing but frozen shattered chunks of meat.'

[MrStabby]

In a one shot campaign I had a good battle. Our part was imprisoned as slaves on a ship and when the slavers were attacked by pirates we made our move to escape. Quickly it became a dash up three decks of a sinking ship through the slavers only to realise we didn't have a plan when we got to the top.

End result was walking on water with the pirate's first mate as hostage in exchange for the ship's rowboat. There were lots of shoves, grapples etc. and the time limited factor changed the pace quite a bit.

[Thisguy_]

In the campaign me and my friends in real life are doing, I used a particularly large owl and thorn whip to yank a guy off a gallows because he was a lead on an ongoing investigation, and I thought it was a bloody blast, but that was probably because my party reacted very well and the DM did an excellent job.

Then there was an entire session in a different campaign with mostly different people in which we were just... on the road. The whole time. There was a thing with a bird, though.

EDIT: Having gone back and seen that you're not asking this just for fun, I'll clarify on how the DM's job was excellent: I got quite excited, and chose to roleplay my character deciding to be a hero for a while, and he reacted by letting me have a moment in the spotlight and providing imagery that splashed against the action nicely. It turned into a back-alley chase, and then devolved into my character panicing and therefore bull****ting his way to "not here or running from this guard anymore." (Notably, I did something to earn being chased only by one guard; the owl turned out to be incredibly distracting.)

With some help from the party, it worked out for me in the end. What the DM did was more than just roll with it, though, he rapidly adapted to this thing I had chosen to do (which he had ABSOLUTELY NO IDEA I was going to do and thus had no plan for the encounter), and he got real comfortable winging it for a while while simultaneously keeping up with scenery and NPC reactions in an appropriate manner.

Therefore, my advice to you is: Get comfortable winging it, as your best laid plans will likely be laid to waste by the players. Everyone has a master of derailment inside them, waiting to burst out of their chest, leaving red meat chunks all over the floor, and sing Hello! Ma Baby.

[Fumble Jack]

Most fun, had a fighter in full plate, risking his life to save people from a burning building, with no time to prepare. Thanks to help from the Cleric in the group, they were able to get everyone out.

Worst, was when I was playing my bard & the DM overestimated the encounter we could handle. 40 thugs & a mage, and a punch to my character's somehow broke his jaw & kept him from doing his verbal spells. It wasn't a crit or special ability, just mundane bludgeoning damage. We were only lvl 7 & just 4 of us.

[Flashy]

Worst, was when I was playing my bard & the DM overestimated the encounter we could handle. 40 thugs & a mage, and a punch to my character's somehow broke his jaw & kept him from doing his verbal spells. It wasn't a crit or special ability, just mundane bludgeoning damage. We were only lvl 7 & just 4 of us.

Yeesh, that rates as scarcely below a deadly encounter for four 15th level characters. Did you survive?

[EvilAnagram]

That would be the time I ruined the DM's plans via overuse of traps.

We were tasked with watching an inn while the owner went out of town. Specifically, we were asked to keep the room he uses for smuggling cargo safe because he didn't trust some of his employees. The key to the holding room was kept in his office. I decided to put nails through the windowsill in the office and grease the area beneath it, set up a snare trap attached to some bells, and set up a crossbow trap and caltrops in the smuggling hold. Then we set up a watch system.

I did all of this with items we had on hand.

The, "find out who the thief is," adventure turned into, "We stopped Todd from stealing ****."

While everyone was debating what to do with the guy who snuck into the office, I cut off his pinky, tied him up, and locked him into his room until his boss came back.

[Fumble Jack]

Yeesh, that rates as scarcely below a deadly encounter for four 15th level characters. Did you survive?

We did survive due to npc interference & the DM realizing when we were close to half hp or less & used up a majority of our resources, that he was going to tpk us, so the town guard came to break all that up.