Bon scott era ac/dc is definitely peak ac/dc. If you listen to any bon scott song vs any brain johnson song you can instantly tell the difference between the two. The songwriting, the style, the sound, the rawness etc.

Not knocking brian johnson, and they clearly got massively more successful with him, but its really not the same band as it was in the 70s. Ive seen them 5 times with johnson, so i dont HATE johnson era ac/dc, but the clear winner is bon scott hands down.