The series, which chronicles the battle for control over a cocaine-trafficking gang, filmed some scenes in Spain and will be sold to foreign broadcasters.
The saga also won viewers' hearts with lighter moments that included Sean Bean, as gang leader Ronnie Phelan, leading a charge of golf buggies to the theme from the film Apocalypse Now.
A scene featuring the cast line-dancing to the 1950s song The House of Bamboo has led to various imitations that have gone viral online.