Any Greek playwright (in verse translation): Euripides, Sophocleas, Aeschylus
Any play by one of the following playwrights: Christopher Marlowe, John Webster, Lope de Vega, Beaumont & Fletcher, Molière (in verse translation), Edmond Rostand, Congreve, Sheridan
And of course, there's always Shakespeare!
Links to Classical Monologues
For both Sexes
Just For Women
Just For Men