You know when you put together two people on the screen it is going to be a success or a flop.  Here is a list that put together of Hollywood's Top-Grossing On-Screen Couples.

#1.) Rupert Grint and Emma Watson, $6.3 billion.

#2.) Viggo Mortensen and Liv Tyler, $3 billion. ( "Lord of the Rings" movies.)

#3.) Orlando Bloom and Kiera Knightley, #2.7 billion. (--The three installments of  "Pirates of the Caribbean" )

#4.) Leonardo DiCaprio and Kate Winslet, $1.9 billion. (--Most of their collective box office comes from "Titanic" . . . $1.8 billion, to be exact. The rest came from their second movie together, "Revolutionary Road".)

#5.) Robert Pattinson and Kristen Stewart, $1.8 billion. (The Twilight Saga, New Moon, Eclipse)

#6.) (tie) Shia LaBeouf and Megan Fox, $1.5 billion. (Transformers and Revenge of the Fallen)

#6.) (tie) Natalie Portman and Hayden Christensen, $1.5 billion. (--For the last two installments of the most recent "Star Wars" trilogy.)

#8.) Robert Downey Jr. and Gwyneth Paltrow, $1.2 billion. (--For "Iron Man" and "Iron Man 2".)

#9.) Ben Stiller and Teri Polo, $1 billion. (--Thanks to "Meet the Parents" and its two sequels, "Meet the Fockers" and "Little Fockers".)

(via Showbiz » The Complete Sheet » Wise Brother Media.)

Most of these movies made money on their own merit, not because of the couple factor (except for maybe Twilight and Titanic).  However, it is interesting to see how Forbes put the list together.