Ginsberg, Howl Bishop, "The Fish" Lowell, “Skunk Hour” Plath, "Daddy" In what ways are different poets more or less confessional than others in this lesson? What characteristics allow us to say, for example, Plath is more personal than Bishop? I am trying to rank the poets I read from least to most confessional.

First, you need to ask yourself, what makes a poet confessional?
A lot of times, a poet will write in a voice specific to the poem, not necessarily about themselves. That doesn't mean that the poem can't be intensely personal and confessional, though.
Confessional poetry expresses private experiences or emotions, something that hadn't really been explored so extensively before the twentieth century.
Ginsberg's poem "Howl" is confessional in its topics. There is a lot of content in this poem and a lot of confession. The poem is raw and honest and talks about drugs, sex, and death in a straightforward and powerful way. It doesn't include the word "I" very much, except in the last section, which makes it feel less personal, though the themes are personal and private.
"The Fish" is also a poem with an unusual topic. In some ways the poem is gross, since it talks about the sea-lice, the blood, and the fish's imminent death. However, it's also a victorious poem, as the speaker realizes that they've caught the fish that four others have attempted to catch. I believe the confession in this poem comes with the fish's release and the ideas that this image presents about freedom as a temporary thing.
In "Skunk Hour," the speaker is in search of love and lamenting that he is alone. Nearby, he can see cars likely occupied by lovers, and yet he is alone with a family of skunks. It's a deeply personal poem of sadness and loneliness, emphasized by the image of skunks as company (something usually very undesirable).
"Daddy" by Plath is filled with confessions, though it's hard to tell which confessions are real. I consider it the most personal of these four poems, as it is written from daughter to father, which typically symbolizes a very intimate relationship. There's a larger story as well, and lots of allusions to World War II, but the heart of the poem is the intensity of emotions in this father-daughter relationship.
https://poets.org/text/brief-guide-confessional-poetry