The villager farm, iron farm, creeper farm, and gold/xp farm! This one was filmed over the course of a week and a half, dang.

Gold/XP Farm:
   • [Simple] ilmango's Gold/XP Farm (117,...  

Iron Farm:
   • 1 Golem Every 2 Seconds?! Custom Iron...  

Villager Breeder:
   • Easy Infinite Villager Breeder For Mi...  

Creeper Farm:
   • Minecraft Creeper Farm - Easy 1500+ G...