My vote goes for Gordon,
Albeit his tenor was short but I will judge by the time they were Corp commanders. I personally liked AP Hill but with him in command of a Corp was somewhat disappointing. Yes, his sickness was the major reason but he became sick at most of the major engagements. I think his nerves brought on his sickness from his youthful past.
Early had his ups and down but he was so dang hard to deal with and Lee I think at times just sent him away to rid himself of his actions.
Ewell, hard to follow Jackson, but he over analyze everything, I bet he study for the longest just how to jump on his horse every morning. He was noncombatant when the fight needed to be pressed.
Anderson did okay, but okay isn't being the third general in line most of the time. Well could be here in the case of those listed after Longstreet and Jackson.