Two television series that I consider to be comic masterpieces:
: each episode is a gem, but you get an entirely different level of comedy by watching the entire series all the way through. Some of the jokes are slowly marinated, making an appearance in one episode only to have the payoff three or four episodes later. Watching it is a constant delight.
"The Fall and Rise of Reginald Perrin"
: This just became available on DVD in the US (don't know about Oz). It's about a man who, dissatisfied with his life, fakes his suicide, and then, under a new identity, ends up reassuming nearly every aspect of his old life. Many of the situations are the same, so it's a show of subtle nuances and small changes -- sorta' like if Philip Glass wrote a sitcom. Somewhat like "Arrested Development," the jokes gradually accumulate, like a snowball rolling downhill, so that they become funnier as the series progresses.