It seems Batman's reign atop the home video charts was a short one. According to The Hollywood Reporter, Mamma Mia! bested The Dark Knight to take the top spot on the national DVD sales charts for the week ending December 21. The Dark Knight did end up doing some solid biz in second place though, amassing 85% of its first week sales in its sophomore week.
The Dark Knight was also topped in the rental charts as well by another newcomer, The Mummy: Tomb of the Dragon Emperor, although The Dark Knight was close on its heels, taking in 93% of The Mummy: Tomb of the Dragon Emperor's rental revenue. Mamma Mia! debuted in third place on the rental charts.
The only place The Dark Knight reigned supreme again was in high-def, taking home the Blu-ray sales crown for the second week in a row. The Mummy: Tomb of the Dragon Emperor debuted in a distant second on the BD charts, with just 30% of The Dark Knight's BD revenue, and Mamma Mia! taking third place on the 1080p charts.