Does everyone have any good stories about non-combat challenges they either went through as players or put their players through as GMs? Either that or a resource that already has a collection of ideas like this. I'm trying to make an exciting dungeon for my players and I'm looking for inspiration. Thanks!

If you don't want them to fight creatures, think about what else could pose a danger.

A dungeon full of flowers, many different kinds. An evil druid has done some "work" on them and each one has a particular effect. Pollen clouds which cause confusion. Flowers that shoot out barbs that do 1 poison damage. Flowers that charm anyone who looks at them too long. You can do many things, and the party must navigate this dungeon...like a plants vs zombies!

I ran a session where the party was simply trying to descend the side of a volcano...while fire giants lobbed flaming boulders at them, a magma flow chased them, and the terrain was very treacherous. The trick was that there were NPCs that were trying to do the same, and the two groups were at odds. To stand and fight was to die, running for your lives meant giving your back to the enemy... Then there was the Titan which emerged from the volcano tossing magma down the mountain at them as they neared the half way point.

The cave in or doomsday device escape can always be entertaining if you play it right. 

I'm actually starting Tales from the Yawning Portal with my group. I know that the last adventure Tomb of Horrors is a high level (above 10, maybe even 14+) that is particularly a low-encounter, high-puzzle dungeon run. Reading through the 3rd adventure, The Hidden Shrine of Tamoachan (for PCs lv5-8) it appears that this is also a high puzzle, very rushed (you can't rest because there is poison that damages them every hour, TONS of drops & also not that many encounters. Only thing from reading reviews is that although the entire Yawning Portal book is all previous adventures converted into 5e, The Hidden Shrine of Tamoachan isn't as properly converted meaning some puzzles have relics from the previous edition that makes them either easier or harder than intended (like the PCs need to scale a wall back when rogues were the only ones able to, or a mediocre Wight with an amulet of immunity to Turn undead when the only way to defeat them was a cleric's turn undead) etc. but still worth a look

Quote from zaxbeez >>

Does everyone have any good stories about non-combat challenges they either went through as players or put their players through as GMs? Either that or a resource that already has a collection of ideas like this. I'm trying to make an exciting dungeon for my players and I'm looking for inspiration. Thanks!

I absolutely love puzzles in my games... I've run through a ton of them and have even run 6 one-shot Puzzle adventures. I could probably help you if you're looking for a ton of puzzle/trap ideas for your dungeon. :)

A simple puzzle I threw at my players was a door with five locks on it, with the following symbols and opening methods:

Blood (dealing yourself 1 damage)
Music (DC 15 performance)
Key (any key can be put into the lock)
Arcane (expend a spell slot)
Ram (DC 15 athletics)

I would really appreciate the help if you could give it. I did a logic puzzle once and it went well, but keeping puzzles vibrant and not exhausting is a challenge for me.