Whats the best transmission oil

I use Honda HP Trans Oil and it seems to be a really good tranny oil. I can't argue as to what's the best because that's all I've ever used and have nothing to compare it to ! I don't think your going to find that at O'Reily's tho.
 
Make sure that what ever oil/ ATF you use Is wet clutch specific.

Needs to be free of friction modifiers.

I personally use bel ray gear saver in my bike, and my brothers kx.

How ever any 10w-30 or 80weight gear oil will work. No modifiers tho!