You do realize you put a Transmission topic in the "Axle" section?
Besides that, most stay away from this topic since we don't have enough info.
Are you AT or MT?
Also, most AT guys run OEM, Amsoil or M1.
Most MT guys run OEM, Amsoil, RP or Redline.
It all comes down to personal preference and cost. Usually RP is easier to get locally so people tend towards. Then some don't care and just pay to have Amsoil shipped.
In the end it is up to you and what you can get in your area.
Anything past that you will get the "I love Amsoil and run it in everything" people and the "RP all the way, its what I have always used" people bickering back and forth.