User blog comment:ImperiexSeed/Strength-scale in Supernatural/@comment-4920092-20120527153146

Here's my revised list, since the completion of Season 7.

God

Death

Michael

Lucifer

Godstiel (think about it…..he HAD to be stronger than Leviathan, because they were part of his power)

Dick Roman

Raphael

Gabriel

Edgar

Ghosts (Stronger) [Like Van Ness]

Famine (able to affect Castiel via his vessel, so more powerful than Pestilence, who only affected Cas because of his lack of angelic power)

Azazel

Lilith

Alastair

Seraph

Leviathan (Stronger)

Angels (above High Tier Monsters, as Castiel was able to slaughter Alphas)

High Tier Monsters [Alphas, Jefferson Starships, Dragons]

Samhain

Leviathan (Weaker)

Crowley

Whore of Babylon

Pestilence

Crossroads Demons

War

Seven Deadly Sins

Black-Eyed Demons (Stronger)

Monsters (Stronger)

Hellhounds

Daeva

Black-Eyed Demons (Weaker)

Monsters (Weaker)

Ghosts (Weaker)

Cherub