Though Talladega Nights: The Ballad of Ricky Bobby repeated at the top of the box office (its total of $23 million was down 50% from last week), the big surprise this weekend was the success of Step Up. The poorly reviewed teen dancing flick earned $21.1 million on fewer than 2500 screens via a per-screen average of $8500, easily the best among mainstream films this week -- who knew that a supporting turn in She's the Man had turned Channing Tatum from former model into box office god? Since the film cost only about $12 million to make, one assumes the people at Buena Vista are doing a little celebrating today.

Also doing solid business during its opening weekend was Oliver Stone's World Trade Center, which made $19 million from Friday to Sunday, earnings that ran its total to $27 million over five days and were good enough for the third spot in the weekend charts. Rounding out the top five were Barnyard which, unaffected by awful reviews, made $10.1 million in its second week in release, and J-horror remake Pulse, which earned only $8.5 million despite an exposure roughly equal to that of Step Up.

Full numbers are after the jump. 1. Talladega Nights: The Ballad of Ricky Bobby, $23 million
2. Step Up, $21.1 million
3. World Trade Center, $19 million
4. Barnyard, $10.1 million
5. Pulse, $8.5 million
6. Pirates of the Caribbean: Dead Man's Chest, $7.2 million
7. The Descent, $4.6 million
7. Zoom, $4.6 million
9. Miami Vice, $4.5 million
10. Monster House, $3.3 million