I didn't really get captivated by The Wire until season 3. It had some really memorable moments, but it was a show I had to force myself through until season 3. Especially season 2, since the dock workers didn't catch my interest.
Going in to season 2 can feel a bit jarring if you were expecting it to continue to be about the drug trade, but the show is about Baltimore and each season shows different aspects of the city. The police/drug trade, the docks, government bureaucracy, school system, and the media. For me it's what makes the wire stand out.