This is a pro blockbuster thread. I was going to add George Lucas but Lucas only mostly has star wars. Who is the ultimate Hollywood blockbuster King of all time? its a close one. I like both directors but Spielberg edges Cameron out. His work is more versatile. his work ethic is more impressive.
Cameron
Terminator 1
Terminator 2
Titanic
Avatar
Aliens
Spielberg
ET
Jurassic Park
Close Encounters of the 3rd Kind
Jaws
Indiana Jones Series.
Saving Private Ryan
Spielberg also has some art house friendly classics like Schindler's List, Lincoln and The Color Purple.