Lord Byron's 1815 poem about King Sennacherib's seige on Jerusalem, especially the Biblical version of the story. I'm not a big fan of religion or religious tales, but just as a work of art -- with its rhythm, metaphors, rhymes, etc. -- this poem is incredible.

Also yes, I was (indirectly) named for Lord Byron. (My dad was named for him and I was named for my dad.) This happens to be the only poem I've read of his at time of recording, actually.