We're talking about the best selling amp here. So it would have to be an amp with some longevity and popularity. And affordability. Configurations of the Peavey Bandit have been around for three and a half decades. Everyone from weekend warriors to seasoned pros use them. And it's reasonably priced. Not to mention the fact that the rugged reliability of the amp is legendary. And though some might turn their nose up at it because it's SS, it delivers good tone.
So I'm guessing that when it comes down to the best selling amp in history, the Peavey Bandit has got to be in the running.