I consider Dennis Potter's "The Singing Detective" the best thing ever to appear on TV. "Karaoke-Cold Lazarus" are contenders for second place. It is vital to see Karaoke first because Dennis Potter wrote them as a part of a whole.
Potter racing against the clock to finish Lazarus before he died. They are funny, weird, mysterious and profound -- a rare combination for any medium. It helps to know a bit of Potter's bio to fully appreciate the depth of this accomplishment.
My favorite moment came when slimy TV producer Siltz exults in the opportunity to own a writer's mind (literally) in order to exploit it. I can imagine the smile on Potter's face when he first conceived that scene, seeing it as a metaphor for his showbiz struggles with the Siltzes of the world.
Anyone who appreciates great writing will love this. Dennis Potter wrote a brilliant script about his own death. I doubt anyone will top his feat for a long time.