Best Mods – Stellaris

In no particular order:

Ringworld start. It allows you to select a ringworld as your home system, ranging from regular 4-space ringworlds, to broken ones you need to repair first, to the awesome 12-segment super ringworld! It allows you to get a bit crazy: go for an extremely small empire (but with 12 25-tile planets) or you can force spawn a custom AI empire that you gave such a huge starting bonus.
More home systems. Comes with a variety of pre-set starting systems, some with quests, many from existing sci-fi settings. I dislike having random home systems, that is why I like this mod.
More Events Mod.
Tiny outliner + various other “Tiny” mods. This reduces the amount of scrolling needed and really improves my gaming quality of life.
Stellaris expansion – Genetics. Gives a few traits that provide extra gene/robo points. Allows for more flexibility without “cheating”.
Additional Traits and VitesseDL’s Expanded Traits. I like having more trait options (especially combined with my mod suggestion #9, see below) and I feel these two mods add fairly balanced traits. There are quite a few other trait mods, but these two are most to my liking.
Expanded Stellaris traditions + Expanded Stellaris Ascension perks (+ resolution fix). Adds a LOT of extra traditions (including swapping traditions for various civics/governments) and the necessary extra Ascension perks. Because I can’t get enough of unity! I feel they are quite decently balanced as well and add a lot of fun extra things to do: city worlds, industrial forge worlds, natural planet ascension, edicts to increase habitat size even further and some weird, multi-tiered prerequisites-required ascension perks as well.
More Leader Traits, Fox Leader Mod, and Faster Leader Pool replacement. Adds extra leader traits, leaders start with 2 traits each and your pool refreshes quicker. I always found leaders to be quite lacking. This makes them a bit more powerful.
Traits & Ethics + Lite 2.5 (one mod). Gives you 6 trait points, 12 trait picks, 4 ethic points, and 4 civic points. Because I can’t ever choose when designing custom empires, this way: I can have my cakes and eat them too! Downside is that random AI empires can be… quite random… so I tend to make a ton of custom empires and force spawn them, so that most of my opponents have coherent traits and governments. NOTE: There are other versions of this mod with more or fewer of all the variables changed. You can pick one depending on your style: this one I mentioned gives quite a huge boost, but there are variants that give fewer trait points, etc.
Anomalies respawner & more anomalies (one mod). Respawns new anomalies every few years and adds additional anomalies as well. You can tweak the rate of respawning anomalies to your liking. Every celestial body without an anomaly, has a chance of spawning a new one. This way, you will have anomalies to discover up to and through the late game.
Guilli’s planet modifiers. Adds fun planet modifiers
Race cheat activator. Fun and ridiculous mod: it allows you to create a custom empire, save it and play with it, even if some design fields are “in the red”. So you can pick four fanatic ethics, or ALL THE POSITIVE TRAITS and simply play with such an empire. It was fun to play a God-like Space Elves empire on a 12-segment ringworld start and scoff at the peasants outside of your comfy, comfy homes…
Repeatable ascension theory tech. Because you need it when using Expanded Ascension perks (see #7)
No Mega structure limits. Build ALL the Megastructures! It allows you to build multiple dyson spheres, etc. And removes a lot of megastructure limitations, you just can’t build more than one megastructre in a single system at a time. So yes: you can build 20 ringworlds in 20 different systems at once (and also build all 4 ringworld segments at once, instead of one after the other). Because fuck balance!
Government variety pack. More civics to choose from!
Slightly powerful starting systems. Gives you just what it says. Great for giving yourself, or the AI a nice little starting boost.
Dynamic difficulty. Add or removes bonuses mid-game, both for AI and for player empires.
Unique system spawn 100%. Spawn all the unique systems and Leviathans, all the time.
Crisis manager, end-game edition. Tweaks crisis strength, spawn chances, etc. during a game
Technology ascendent. A bit ridiculous/unbalanced, but still fun. Allows for a few extra super techs.
Maximum planet capitals. Because I hate starting on an 18 tile planet and later finding a 25 tile planet or building a ringworld… I want my capital to stay my capital forever and be the best planet all the time. Also works for the AI
PJs mods. Quite a number of small mods, adding things like extra buildings, techs, etc. Check them out and see which you like
ST New Horizons. Star Trek total overhaul mod. Extremely impressive and changes the Stellaris gameplay feel by quite a lot. Check it out.