What are the three or four most striking figures of speech in the poem? How would each be categorized (metaphor, simile, and so on), and why is each so impressive?

"Tell me what thy lordly name is on the Night's Plutonian shore!" - mythological allusion to Pluto, god of the underworld

"Perched upon a bust of Pallas" - reference (mythological) to Pallas Athena, goddess for the Greeks

"Quaff, oh quaff, this kind nepenthe" - a reference to medicine and the Greek belief that nepenthe could ease pain and grief by causing forgetfulness

All are impressive because of the depth of Poe's knowledge to include them in this poem.