Choose a stanza of this poem that you believe is particularly strong and offer a brief close reading that supports your choice. You may focus on any aspect of the stanza that strikes your fancy (e.g., Byron's satire, his handling of the technical features of the stanza, his narrative strategy, etc.).
To answer this, I'll have to quote the stanza in its entirety initially in order to analyse how it functions:
Brave men were living before Agamemnon
And since, exceeding valorous and sage,
A good deal like him too, though quite the same none;
But then they shone not on the poet's page,
And so have been forgotten:—I condemn none,
But can't find any in the present age
Fit for my poem (that is, for my new one);
So, as I said, I 'll take my friend Don Juan.
The stanza comes early in Canto One as Byron introduces Don Juan as his choice of heroes, the subject of his satirical epic. He has previously considered the merits of various other contemporary figures, including in the previous stanza, Lord Nelson, whose death in 1805 at the Battle of Trafalgar had made him the hero of the age, at least until the later defeat of Napoleon at Waterloo in 1815, at which point, Byron satirically observes that 'the army's grown more popular'. In this stanza, therefore, Byron moves from the particular to the abstract, considering the broad sweep of heroic mankind from 'Agememnon/And since'. The use of the run on line from line one to two of the stanza, allied to the abrupt pause of the caesura after 'since' emphasises the sweep of history past the time of the ancient Greeks and takes on one of the heroes of the Trojan wars before sweeping onward. However, Agamemnon is named here particularly in order to force the half-rhyme with 'none' at the end of the third line. The construction of the third line is witty and well-contrived to force a rhyme. The line is again constructed using a caesura, separating the other heroes' names in the previous lines who are 'a good deal like him' to Don Juan. Don Juan is rhythmically separated from he other heroes by the caesura and by the deliberately forced syntax of the second part of the line which places the negative 'none' at the end of the line - 'though quite the same none' - both in order to partially rhyme with 'Agamemnon' (in the partial rhyme of 'non' and 'nun' sounds) and to sound awkward precisely because Don Juan, a satiric hero, is like 'none' of the other heroes named precisely because he is not really a hero, rather a man who women are drawn to and whose adventures are amatory in nature rather than martial or intellectual like the other heroes named and so 'none' are 'quite the same' as him. The awkwardness of the syntax hints at the awkwardness of the comparison and shows perhaps why Don Juan has 'shone' on the 'page' - while the other heroes' acts may have been more valiant, none is as amusing to Byron as the alluring Don Juan and so, in an imperious sweep of the passive voice, they 'have been forgotten' in favour of Don Juan. By using the passive voice here, Byron suggests that the act of forgetting these other heroes has not been his own choice where, of course, we the reader know that it is entirely his decision. Moreover, after this imperious tone, Byron's narrative voice lurches immediately to a much less formal register, the use of 'as I said' assuming a conversational tone, as if the reader is in dialogue with the narrator, before identifying Don Juan as his 'friend'. Of course, the knowing reader of Byron's 'poem' and observer of the 'modern age' that he writes about will know the similarity of Byron to his 'friend' given that Byron, like Don Juan, was embroiled in multiple high-profile affairs with aristocratic women - his 'friend' is, indeed, a satirical reflection of his own infamy, making this an amusing and self-reflexive stanza.