Kristen Stewart & Robert Pattinson are highest-grossing onscreen couple: Robert Pattinson, 24, and Kristen Stewart, 20, have helped the Twilight films make a ton of money — but they’re not even close to being the highest-grossing onscreen couple of all time!

That honor goes to Harry Potter duo Rupert Grint, 22, and Emma Watson, 20, whose Ron and Hermione have anchored the seven films in the series to a staggering $6.3 billion worldwide. The final film, Harry Potter and the Deathly Hallows, Part 2 will come out in summer 2011.

The list, compiled by Forbes, features couples that have appeared in at least two films together. Coming in at number two is Viggo Mortensen, 52, and Liv Tyler, 33, from the The Lord of the Rings movies, which grossed $3 billion. Pirates of the Caribbean lovebirds Orlando Bloom, 33, and Keira Knightley, 25, whose films netted $2.7 billion. No. 4 belongs to Leonardo DiCaprio, 36, and Kate Winslet, 35, whose romance in the massively popular Titanic buoyed their gross to $1.9 billion.

How did Bella and Edward fare? The Twilight movies have grossed $1.8 billion dollars so far, with two more sure-to-be-massive installments coming this year and next. We’re sure Twi-hards will come out in drove to support their favorite couple!