RE: ? X ? for max gains?
There isn't one.
2x12, 3x10, 4x8, 5x5, 3x6, 5x3, 8x1
It all works, the secret is 'consistency'.
You have to pick a routine based on the compound movements with the right rep/set range (suitable for you) that doesn't wear you out after just a few weeks of training, thus allowing for weeks/months of consistent training.
You can change the rep/set scheme every few weeks if needed as long as you're getting some consistant hard training under your belt you'll make progress (not considering shortcomings in your diet and rest).
I've also found not training to failure on a regular basis helps keep the cycle going.
All IMO ofcourse