Overview:
Some of the key mods related to world generation are made by YUNG. These mods alter the naturally generated structures, such as the End Stronghold and Desert Temples. Additionally, there is Biomes O' Plenty for the rest of the world generation. Regarding technical mods, there is the Thermal Expansion series and also Mekanism. For those who want to delve into ProjectE, it is also included. Storage management is much simpler with Applied Energistics 2.
There are many more mods for you to explore, so enjoy, and thanks for downloading.
-GaffXD :)