Check out Two Steps from Hell. They compose epic tracks for movie/game trailers, and I can almost guarantee you've heard some of their work without knowing. It's very extensive, and plays in trailers for some of the most popular games/movies today.
In particular, the group's music has been used in trailers for such films as Harry Potter and the Order of the Phoenix, Harry Potter and the Deathly Hallows: Part 1, Harry Potter and the Deathly Hallows: Part 2, Star Trek, The Dark Knight, The Fighter, Rise of the Planet of the Apes, Tron: Legacy, Anna Karenina, No Country for Old Men, 2012, Captain America: The First Avenger, X-Men Origins: Wolverine, X-Men: First Class, Pirates of the Caribbean: At World's End, Super 8, Inception, Drive Angry, The Twilight Saga: Eclipse, Hugo, John Carter, The Town, Priest and Prince of Persia, as well as video games such as Resident Evil 6, Mass Effect 2, Mass Effect 3, Killzone 3, and Star Wars: The Old Republic and television shows such as Doctor Who, Game of Thrones, Sherlock, Revolution, Homeland, The Walking Dead and Merlin, and during the 2012 London Olympics.
Their song "Heart of Courage" was also used in the beginning of UEFA Euro 2012 matches and in the beginning of the London 2012 Olympic games athletics finals.
If you want to sample their music, I'd recommend search Two Steps from Hell on iTunes, then choose the album archangel, and sample the songs 'Love and Loss', 'Norwegian Pirate', and 'Ironwing'.
They're also on YouTube of course.
Enjoy. Let me know your thoughts on these guys. They have four public albums available on iTunes right now, a fifth coming via Thomas Bergersen.