Tannhaeuser/YMMV

Alternative Character Interpretation: Depending on the production, Heinrich has been depicted as everything from a weak-willed sensualist to a bold artist rebelling against a repressive proto-Nazi society. Venus is sometimes presented as the old Paganism, the life-giving force of sex, the source of true-inspiration, or a mere figment of Heinrich's psychotic imagination.
Crowning Moment of Awesome: The tour-de-force at the end of the second act, when the fortissimo, mostly tenor, baritone, and bass, ensemble of the nobles is interrupted unexpectedly by the pianissimo soprano chorus of the younger pilgrims. Breath-taking.
He Wasted A Perfectly Good Plot: No less a figure than G. K. Chesterton complained that Wagner's last-minute redemption of Heinrich spoiled the entire point of the original legend. (To be sure, he was less than familiar with the opera, having no ear for music.)
Purity Sue: Elisabeth