A Midsummer Night's Dream
Four lovers flee into a wood outside Athens and wake up wrong: the fairy king is feuding with his queen, a mischief-spirit is dosing sleepers with a love-flower, and a weaver named Bottom is given the head of an ass and the affections of the fairy queen. It is Shakespeare's most perfect comic machine, three worlds (court, fairies, amateur actors) interlocking without a wasted scene. Underneath the moonlight it asks a genuinely unsettling question: if love can be switched by a drop on the eyelids, what was it before? The rude mechanicals' play-within-the-play is still the funniest thing he ever wrote.
The lovers are interchangeable on purpose, which is the joke and also the problem: two acts of Lysander and Demetrius is two acts of the same man arguing with himself. The frame plot hands Hippolyta to Theseus as a war prize and never looks back, and Oberon ends the play having drugged his wife into loving a donkey and won custody of a child by it: a resolution the moonlight is doing a lot of work to soften. Delightful in performance; on the page, the machinery shows.
The case for it and the rest of the canon open with Pro.
