My boy @GasPlease currently pushes autos the furthest of anyone on site I believe.
He has fully mastered the @420autoflower technique. 420autoflower was (at least to my knowledge) the first guy to put all of these different style training techniques together in order to achieve autoflowers over the 3 pound mark.
He is not currently on our new site since we changed over, but that is because he is not currently growing.
The man himself should be back within a few months 
There are several other growers that also produce massive plants, but I do believe Gas takes the cake at the moment