Air Date: 10/9/11
Walter White (Bryan Cranston) finally defeats the diabolical Chicken Man, but at the cost of a big chunk of his soul. Both Walt and Gus (Giancarlo Esposito) realize that Jesse's (Aaron Paul) loyalty is ultimately where victory lies, and the duplicitous way in which Walter wins his partner back (non-fatally poisoning his girlfriend's kid and blaming Gus) is reprehensible, and a major stepping stone in his journey from mild-mannered teacher to meth drug lord.
That's to say nothing of the genius plan that finally takes Gus out, which wraps up an epic, decades-long conflict and makes fantastic use of Uncle Tio's (Mark Margolis) bell. The revelation that the finale's title was to be taken literally stands as one of the craziest moments of television.