Boosted by unexpectedly strong word-of-mouth and generous reviews, 'Transformers: Dark of the Moon' was number one for the second weekend in a row, becoming the top-grossing movie of 2011 thus far with a total take of $261.0 million.

Coming in second, the Jennifer Aniston-featured dark comedy 'Horrible Bosses' earned an estimated $28.1 million, while the family flick 'Zookeeper' came in third with $21.0 million.

Here's a recap of all five of this weekend's top box-office earners.

'Transformers: Dark of the Moon' - $47.0 million (4,088 screens), $261.0 million total

'Horrible Bosses' - $28.1 million (3,040 screens), new release

'Zookeeper' - $21.0 million (3,482 screens), new release

'Cars 2' - $15.2 million (3,990 screens), $148.8 million total

'Bad Teacher' - $9.0 million (2,962 screens), $78.8 million total