It has a little bit of everything, but let's break it down a little further!
For the engineers and industrialists:
Mekanism (Mine extra ores, make cool machines, and operate on an industrial level!) and Immersive Engineering (Electrocute yourself with high voltage wires! And power your machines, I guess...)
For the witches:
Ars Noveau (Make a cool spellbook and collect glyphs to build your own spells! Make a spell that lights off 50 fireworks at once and then use it in a small room!)
For the farmers:
Pams HarvestCraft (Harvest and cook with new crops and fruit trees!)
For everyone:
Mousetweaks and JEI, quality of life improvements that show what you're looking at, plus loads of tiny adjustments and changes to make the game more pleasant to play.

