For me Interstellar by far. Star Wars Episode 7 will probably be the bigger hit (might even reach Avatar's record) as it will appeal to he masses.
But we all know Interstellar is going to be far superior. It's Christopher Nolan, 'nuff said. JJ Abrams is a wannabe Christopher Nolan, you only have to watch Star Trek Into Darkness to see how much he ripped off The Dark Knight