Imma say Avengers. But I can see Star Wars over overtaking it....
I honestly feel Avengers will break the record followed by Star Wars later this year. The queen shall show the lessors how its done 2016, Batman vs Superman will obliterate the record.. Bookmark me.
My predictions:
Avengers will take the WW opening record, fastest to $1 billion record and become the third highest grossing movie ever, maybe inching past Titanic into second place but unlikely
Star Wars will take the domestic opening record and finish overall well ahead at home but lower internationally. It'll be Top 3 domestic box office releases ever, again maybe passing Titanic but definitely not Avatar
Batman Vs Superman will open strong and be a big hit ($1 billion is certainly likely with good word-of-mouth) but won't make as much as the other two.
Star Wars. None of these has a fanbase overlapping generations like Star Wars, and it's been 10 years since the latest episode came out, so it's going to **** on each movie released this year I think. Of course Avengers will slay too, but its fanbase is not as diverse as SW's.
BvS will feed off avengers it will open big and break a few records but ultimately how it finishes depends on how good it is, either way it will make tons of money and the survival of the shared universe franchise will depend on the next movie after BvS.
Avengers will def break every record FF7 has just set and more, star wars will break USA and china box office records but the rest of the world wont respond as well
Avengers: Bigger OS
SW: Bigger Domestic
MJP2: More critical acclaim therefore a better movie
All in all, SW will be huge in the states but it never was a force overseas so Avengers will shine there... & if the Avengers is bigger in the rest of the world it will outgross SW
Fun fact: Last SWs movie (in 2005) got scalped by the first Harry Potter movie