The Entertainment Retailers Association (ERA) combines sales of DVDs, Blu-rays, games and music albums into one catch-all chart of the best-selling entertainment commodities in Britain.
Sky News reports that The Twilight Saga: Breaking Dawn - Part 1 topped the chart for the first half of 2012, selling 1.2 million copies.
It sold nearly twice as much as its closest rival, pop compilation Now That's What I Call Music 81, which sold 667,932 copies.
There was good news for movie and television studios, with an increase in the presence of top-selling Blu-rays and DVDs in the chart: they accounted for 21 of the top 40 sellers, as opposed to 19 in 2011.
Movies and TV shows with British links that fared well in the chart included Mrs Brown's Boys, Sherlock Holmes: A Game of Shadows, Tinker Tailor Soldier Spy and War Horse.
However, overall entertainment sales were down in the first half of the year, something attributed by ERA director general Kim Bayley to the traditional focus of entertainment companies on the Christmas period.
Bayley went on to say: "Films and TV on video was the highlight of the entertainment market in a tough first half, [and] it is striking to see the success of British-themed content".