Exploration:

- The Valkyrian Skies mod in conjunction with Eureka Airships allows for easier and more interesting exploration of your world

- New structures added by various mods, such as Tetra, add a reason to go out exploring

- Create: Steam and Rails adds yet another interesting method of transportation and infrastructure in the form of trains

- The Sophisticated Backpacks mod adds tiered portable storage that is upgradable in many different ways, making it perfect for long trips.

Magic:

- Iron's Spells 'n Spellbooks adds a wide variety of magic abilities to gain and upgrade.

- Tetra adds fully customizable weaponry, which can be enchanted and upgraded using base enchanted books, or with special items and blocks obtained from exploration

- Waystones adds a vanilla-friendly way to teleport, by using a difficult crafting recipe or requiring exploration.

Technology:

- The Create mod, with some add-ons, adds full-fledged mechanical systems, allowing you to automate the creation of almost any material, and build complex structures

- The Music Maker Mod adds the ability to create music and play it on a wide variety of instruments

Multiplayer:

- Numismatic Overhaul (adds full system for money, replacing villager currency systems and an alternative to using diamonds for player trading)

- Corpse mod

- Armor Poser

- Cosmetic Armor Reworked

- Customizable Player Models

- Callable Horses

And more!

Suserver III

Anvil Never Too Expensive

AppleSkin

Armor Poser

Balm

Blueprint

Caelus API

Callable Horses

Collective

Comforts

Controlling

Corpse

Cosmetic Armor Reworked

Create

Create Big Cannons

Create: Enchantment Industry

Create: Steam 'n' Rails

CreativeCore

Curios API (Forge/NeoForge)

Customizable Player Models

Damage Tilt