Given that we're planning to start a new world for 1.21, I figured now was the time to put up a list of potential data packs for consideration. Nothing too game altering, just some cool things that might add to the experience.


Wandering Trader mini blocks
Adds new trades to the Wandering Trader to make them more desirable. The new trades are mini-blocks, ie. custom mob heads that look like smaller versions of blocks. Here's an old video of Xisuma showing it off:
https://www.youtube.com/watch?v=L3En7cuOdHY


Custom Armor Stands
You can obtain a special book that allows you to customise armor stands in the world in so many ways, too many to list here. One of the appeals to me though is the ability to put any item in the hand(s) of the armor stand, then make it defy gravity, float it up, turn it invisible, and make it look like the item is displayed on a hanging sign - a great way to signify the purpose of a building in your base!

It also has the ability to toggle item frame visibility!

Here's a video of ZombieCleo showing this one off, as they are very experienced with it:
https://www.youtube.com/watch?v=nV9-_RacnoI


Custom Recipes
Here are some custom recipes for consideration too:

Wood items (planks, trapdoors, gates, fences, etc.) craftable on the Stonecutter. This would need a bigger discussion about ratios as it can't quite match the Log -> final item ratio, but it infinitely improves the wood item crafting experience IMO

Glass smelting via Blast Furnace (to improve turnover speed)

Edited 11th Nov based on in-game chat

I would like to see a server-side mod making the delay of the copper bulbs 1 game tick. It isn't a datapack, but it is QOL.

Datapacks I would suggest (on top of the ones already named):
(These are from vanilla tweaks)
The datapacks we already have
- So, Shulkers always drop 2 shells and animal heads.
Multiplayer Sleep
- I've always thought that the /afk method is a bit strange, so I suggest this.
player head drops
- Just think its nice, though not neccesary

Faster minecarts (might need a mod instead of datapack)
- I've always been a fan of trains and want to make a large rail network on the server, especcially now that you can go into the nether with them. However, minecarts are... not fast, and therefore are not a competitor to the elytra.

I feel like with the autocrafter, making a stackable dispenser recipe is unnecessary.

Though most of the packs suggested so far are Vanilla Tweaks, I think it's worth providing a link to the whole site for those who aren't aware. Vanilla Tweaks has a plethora of QoL additions that are entirely interoperable and (mostly) balanced to vanilla, down to just singular crafting recipe changes. A quick browse might show you things you didn't even know you wanted.

Funny enough I was just thinking about some of these things as well.

Invisible item frames are a must have for me, although these can also easily be achieved with texture packs.

Edit: of course, the nice thing about a data pack is you could select which item frames are invisible, whereas a texture pack you could not.

Just feel like throwing in my two cents on this: I'd like to avoid changing crafting recipes, but the armor stand book and player head drops would certainly be nice. I'd advocate against the Multiplayer Sleep datapack, as the current method still allows other players to choose whether or not to skip the night which I think is a good thing to have. I agree with iPhoenix on the autocrafter.

Invisible item frames come with the Armor Statues datapack, where you can turn the closest item frame to you invisible, so I think this datapack would be among my top choices.

That’s true. Admittedly, I originally wrote this list ages ago before the autocrafter was announced.

I'dd also like Shulker+
(https://www.curseforge.com/minecraft/mc-mods/shulker)