Best amp I've ever owned for pure power and tone that routinely sounded good in any situation was an Ampeg SVT-CL. Though technically 300W, it's 300 valve watts and is a beast. It's also a beast to carry. Even so, I wish I still owned it.
The best amp I've ever owned for pure power and tone that routinely sounded good in any situation THAT CAN REASONABLY BE CARRIED by one person without bursting one's scrotum is the Gallien-Krueger MB500 Fusion, a fantastically versatile amp that I really, really, wish I hadn't sold. That is all.