The best Civilization V mods
Now that Civilization V has had a few years to mature, it's gone from Civ IV's scrawnier younger sibling to a full-grown adult (it's even shaving now, we hear). Firaxis' official patches and expansions—Gods & Kings, and now the upcoming Brave New World—have done a lot to help fill-out Civ V's feature set, but the amazing modding community has also been twisting knobs and adding content, with over 1500 mods available on Steam Workshop.
This list features most of our favorites of the bunch, but we've opted to leave out single civs and single maps (of which there are many) to focus on interface, graphics, and larger gameplay and campaign mods. For a quick glance at all our recommendations, check our Steam Workshop collection, and you're encouraged to recommend your favorites in the comments.
Utilities and Interface Tweaks
Civ V Unofficial Patch
Start here. The Unofficial Patch is a collection of upgrades which add detail to the interface such as promotion icons over units, city banners which show turns until border expansion, and an improved city view. Those and many more tweaks make it easier to see data at a glance, and there are also tools for modders, if you're looking to make this list's next addition.
You'll need the Gods & Kings version of the Unofficial Patch if you want to enjoy the G&K Enhanced Mod mentioned later (and I recommend you do). If you don't own the Gods & Kings expansion, grab Vanilla Enhanced, which includes the original Unofficial Patch.
Really Advanced Setup
Since we're all Really Advanced Players here, we can use Really Advanced Setup to do really advanced things. Really Advanced Setup lets you deactivate civs we don't want randomly chosen, decide if you want to start near the ocean, a river, or in a certain biome (grass, plains, hills, forest, etc.), set starting bonuses, change starting units, and more.
As I already obsess over designing the perfect starting scenario, this mod is dangerous—try not to spend more time tweaking resource distribution than playing.
Using Perlin noise PerfectWorld 3 builds an elevation map to create landforms, then uses "a simplified model of geostrophic and monsoon wind patterns" to generate climate—the results as I've observed them are notably more natural maps. The version on Steam Workshop was not uploaded by the creator, but works, and the original thread can be found at Civilization Fanatics
With a city or Settler selected, City Limits displays the maximum area city borders can expand into. With a Settler selected, it also shows the overlap your potential new city will have with adjacent settlements, which is useful for optimizing placement. Make this simple but very helpful mod yours on Steam Workshop.
Faster Aircraft Animations
Don't start an industrial revolution without it! Get it on Steam Workshop.
If you graphed the crossover between people who like Civ V and people who like graphs, you'd be wasting your time—everyone likes graphs. Get lots of them with InfoAddict, which comes in Gods & Kings and vanilla flavors and charts the world's progress, international relationships, and demographics with unmatched detail.