Nominate a mod to be included in RimWorld!

[Hieronymous Alloy]

Quality Builder, Prepare Carefully, Defensive Positions.

Oh, and most of all, the Blueprints mod, so you can save templates. Except expand it so you can save "planning tool" outlines.

[sirgzu]

My top pick goes for Combat Realism if only for the reworked ballistics.
Actually CR makes ranged weapons and defenses too imbalanced. Somewhere in the middle would be nice. This is especially annoying while trying to hunt small game. Shooting a rabbit should be somewhat easier considering the smaller takeway, yet takes much longer because the aim is so bad...

All of Fluffy's mods (and other UI mods in general EDIT => this , Moody and the outdated inventory mod was handy as well)

All QoL mods (AllowTool, Enhanced Crafting, Hauling Hysteresis, Quality Builder etc...)

P-Music

[ChJees]

Freezers mod.
It is so useful . Maybe have a microwave to go with heating up the frozen food too, lol.

https://ludeon.com/forums/index.php?topic=26893.0

[SilentP]

Prepare Carefully, mending, vanilla turrets

[Raccoon]

 Combat Realism + EPOE

[Ninjakitty66]

I have to agree combat realism is a great mod, even if you don't like the ammo crafting. I think it should be added with the option with or without ammo crafting. The reloading time, spraying from LMGs/Miniguns, these are a few good features with a few more added.

[killerx243]

Hospitality.

[Hieronymous Alloy]

"I Can Fix It". Automatically orders colonists to rebuild destroyed things.

[Daguest]

-The "animals" part of Colony manager. Would allow to automatically tame, train and slaughter animals, so you'll avoid chicken explosion, and the micromanaging chore farm animal can be. I don't use farm animal that reproduce quickly without it.
http://steamcommunity.com/sharedfiles/filedetails/?id=715565262

The "mod that would be a massive QoL" :
-Haul priority, the first mod I looked for, and downloaded. I have a hard time without it.
http://steamcommunity.com/sharedfiles/filedetails/?id=725714675
-Vein miner (allow you to mine a entire vein at once, also several brushes for mining)

The "big mod that I can't play without" :
-Power switch. So I can shutdown my growing area at night automatically, my turrets when no enemies are around, my prison when there is no prisoners, my hospital when nobody is injured and so on.
http://steamcommunity.com/sharedfiles/filedetails/?id=717632155
-Colony manager, mentioned earlier for the animal tab, but otherwise a very useful mod that will drastically reduce micromanagement.
http://steamcommunity.com/sharedfiles/filedetails/?id=715565262

The "very small mods that makes a huge difference" :
-Work tab (expand the work tab). The ability to have more than 4 priority order would be good enough though.
http://steamcommunity.com/sharedfiles/filedetails/?id=725219116
-Quality builder (allow to only have the highest construction colonist to build furniture). No more construction 2 building your royal bed (shoddy), when your construction 19 is idle.
http://steamcommunity.com/sharedfiles/filedetails/?id=754637870
-Silent door. As an option or something. Because having the constant "shh shh" by mid-late game on a mid sized colony is seriously annoying.
http://steamcommunity.com/sharedfiles/filedetails/?id=726951285

The not so easy, but would be great :
-Prepare carefully (I think that one is by far the most popular, and for good reasons)
-Extended storage (allow to build containers to stack more stuff). Otherwise my colonies ends up looking like a giant warehouse, with a few bedrooms in the middle.
http://steamcommunity.com/sharedfiles/filedetails/?id=731732064
-RT fuse. Because Zzzzttt is annoying, random, and not realistic. It doesn't remove it entirely, I find it balanced.
http://steamcommunity.com/sharedfiles/filedetails/?id=728314182

[porcupine]

Without the slightest doubt: COMBAT REALISM. 

It's by far the best mod, it provides considerably more "meat" to Rimworld, vastly increases replay-ability, and contains a slew of features/attributes/etc. which should have been in vanilla (IE: Ammo, weight consideration, equipment control, carrying rations, reloading, etc.).

I stopped playing Rimworld with Alpha 13, after the last update to Combat Realism.  It wasn't incidental, it was because new Alpha's came out, and I didn't see updates to CR (whose core author stopped updating, specifically because he had issues with how Tynan was handling updates/changes/etc., forcing a ton of re-work with every new alpha).

[etoire]

Wildlife Tab.

[☢FLAY☢]

Hospitality, Expanded Prosthetics & Organ Engineering and Prepare Carefully, a dog said

[Thorbane]

The Achtung mod.  https://ludeon.com/forums/index.php?topic=22130.0
It allows:

• Organizing your colonists into a firing line in 1 click
• Order all your selected colonists that can fire at something to do so, without also ordering any that can't to go running to their death
• Order selected colonist to melee something in one click instead of individually
• Order colonists to clean a room. (great for the hospital when you want it clean now)

[Apex]

I like Orions hospitality and feel it would fit into the game easily and adds an awful lot of playability.

[Hechtic]

Zorba's Crafting Hysteresis would be a great mod to add to the base game. The ability to make bills pause on completion and restart after the stockpile gets down to a certain number, instead of the stockpile being 98% full but yet they hop to refill would be great.