It usually takes great shows a little time to find their sea legs. Characters are raw and undeveloped, actors aren't quite getting the kind of direction they'll get a season or two down the road, writers a little uncertain where they're going so they leave themselves some wiggle room. Not so with Arrested Development. From the Pilot on it delivers hilarious lines, a consistent yet developing chemistry between characters, and as much consistency in writing as you can expect from a show that isn't especially plot-based.
Micheal (Jason Bateman) works for his father at a housing development company named after the family: The Bluth Company. His siblings are ne'er-do-well's who have never worked in their lives and still pick up company paychecks. When his father is arrested (are you starting to see where the name came from?) for reasons that remain vague during the first season, and the company falls apart, Micheal steps in to keep it, and the family together.
George Micheal, his son, is his conscience and the person who convinces him that his family is worth keeping around. His sister is generally smarter than the rest of the family, but hides it behind her vanity most of the time while she struggles to make her marriage to her clueless husband work. Her clueless husband is therapist turned actor with a knack for Freudian slips. His brother JOB is a magician whose own Magicians Alliance has black-listed him from working in the industry because he gave away a trick in a hopeless effort to win his father's affection. Buster is a momma's boy to a mother who barely qualifies as a mother. Together, they're the most dysfunctional family ever.
What really makes the show work are the individual scenes. Lines are delivered and countered with gut-splitting comedic timing and clever writing that isn't normally found in the sitcom genre. It's not a family friendly show, content (almost entirely in the form of dialogue) is often pushing the boundaries of what censors will allow, but usually what comes to the screen is more subtle than other sitcoms as well.
If you haven't seen it yet, do yourself a favor, and buy this show.