Avengers: Age of Ultron - $27.6m preview ($191.27m opening)
Captain America: Civil War - $25m preview ($179.14m opening)
Marvel's The Avengers - $18.7m from midnight screenings ($207.44m opening)
Iron Man 3 - $15.6m preview ($174.14m opening)
Guardians of the Galaxy - $11.2m preview ($94.32m opening)
Captain America: The Winter Soldier - $10.3m preview ($95.02m opening)
Doctor Strange - $9.4m preview ($???m opening)
Iron Man 2 - $7.5m from midnight screenings ($128.12m opening)
Thor: The Dark World - $7.1m preview ($85.74m opening)
Ant-Man - $6.4m preview ($57.23m opening)
Captain America: The First Avenger - $4m from midnight screenings ($65.06m opening)
Thor - $3.25m from midnight screenings ($65.72m opening)
Iron Man - $1.7m from midnight screenings ($98.6m opening)
The Incredible Hulk - $1.6m from midnight screenings ($55.4m opening)
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I'd guess between 80 and 90 million opening US weekend.