Which cube is the best for raising a potential to legendary?

If you have the funds, get an SE neb so you can get a 9% or 12% stat line instead (since A nebs only give 3% stat, SE is far superior). Also, I used 66 super cubes during the miracle time. All my items were already epic. Got 3 items to unique, and one to legendary.

I got a junk glove solely for this purpose. I don't even have 50mil so the SE neb is out of the question .

For future reference I'm using a reverse engnaw (or whatever the thief glove is called).