Best rear end fluid?

[Murder after M]

Gonna change the fluid soon.....what do you guys recommend?

 

[liv4gnz]

lucas 80/90 you dont need the additive with it, atleast thats what it says

 

[coach]

X2 Lucas, but I still put the posi lube in.

 

[TurboTnZ06]

I use Royal Purple in my Z06, Suburban and Buick.