Minecraft YouTubers Pixlriffs (http://youtube.com/Pixlriffs) and Python (http://youtube.com/PythonMC) embark on their series, Minecraft Harmony, a very lightly modded Minecraft experience with an RPG style levelling system (using the 'Levels' and 'Level Up!' mods) and new realms to explore while remaining very much Vanilla Minecraft with the 'Biome Bundle' mod as the centrepiece of the pack.
There are also a few quality of life mods such as 'VeinMiner', 'EasierVillagerTrading', 'Inventory Tweaks', 'JEI' and more, some visual enhancement mods such as 'Better Foliage', 'Tough As Nails' (Only the seasons aspect is enabled for this mod!), 'Dynamic Surroundings' and a couple quirky ones here and there too like the infamous 'Blood Moon' mod and also the 'Concrete' and 'Terracotta' mods, which simply adds the 1.12 concrete and glazed terracotta from Vanilla into 1.11.2 here!
Hope you enjoy the pack. All feedback and suggestions are welcome as always and happy Minecrafting!