Ok, I'm looking for classical music with orchestras kinda like the Requiem for a Dream theme with full orchestra (used in Two Towers trailer) and music that is used in the Spider-Man 2 trailer. Not those exact pieces but music in that vein. Could you give me some recommendations with artists and songs please? I hope you understand what I am looking for I can't really describe it any other way.

Well, the Requiem for a Dream theme is done by the Kronos Quartet and they have many amazing albums. Caravan is my personal favorite of theres.

Orff's Carmina Burana
and
Holst's The Planets

might just be something you'd enjoy. The first has amazing vocals that I am sure you have heard many times before due to Hollywood's enjoyment of using it in film trailers.

Other's that you might enjoy:

Stravinky's Firebird Suite
Grieg's Peer Gynt Suites (especially In The Hall of the Mountain King)
Anything by Wagner
Mussorgsky's Pictures at an Exhibition/Night on a Bare Mountain

For something different try some of the Philip Glass scores (ie: Koyaqyatsi or Powaquatsi)

Hope that helps. Enjoy.

Thank you very much!

I just bought tickets this morning to see their NASA show. I can't wait.

Kronos Quartet have performed in a number of film scores, including Heat (by Elliot Goldenthal; there is actually very little of the music on the cd, but what's there is good) and Dracula by Philip Glass. Requiem for a Dream was also performed by the "Kronos Guys". The theme is predominantly string. If you're looking for the same sort of orchestration on RFAD, you should look out for String Quartets. My recommendation would be by Edward Elgar.

Come to think about it, you should really like the Enigma Variations by Edward Elgar! (same sort of gloomyness as RFAD, though not as "choppy")

try the ninth gate soundtrack and bram stokers dracula soundtrack.