"Entourage" gets a little bit worse the more famous and successful the characters become. "Extras" slipped down the same slope, only much faster and harder. There's little drama or humor about guys who can get laid at will. I still love it and will eagerly tune in for the next season in September, but it's appeal is waning.
"Conchords," on the other hand, is a show about unsuccessful dweebs with the scoring ability of the San Francisco 49ers' offense. Shows about losers who will never do well can be good perpetually. It'll be even better when they're older and unsuccessful, although they say they're going to stop after this season. Hopefully they're just trying to get more money.