IronFile

The Mod descriptions 

Create.                        Fun tech and factory mod

Refined storage.         Useful for big organised storage in a small space

JEI.                              Useful for knowing info about blocks and other

Valkyrie + Eureka.       You can play with physics and build airships

The one probe.           Useful for knowing blocks and entities state 

Xaero's minimap.        Good and detailed mapping 

FTB ultimate.               Makes mining quick and easy 

Better achievements   Makes the achievement menu more understandable