Careful, the original soundtrack which you may find on sale is original music recorded for the film (by Andrew Michaels). I assume you are after Mad World and the other 'songs'.
Disc: 1
1. Never Tear Us Apart - INXS
2. Head Over Heels - Tears For Fears
3. Under The Milky Way - The Church
4. Lucid Memory - Sam Bauer & Gerard Bauer
5. Lucid Assembly - Gerard Bauer & Mike Bauer
6. Ave Maria - Giulio Caccini & Paul pritchard
7. For Whom The Bells Toll - Steve Baker & Carmen Daye
8. Show Me (Part 1) - Quito Colayeo & Tony Hertz
9. Notorious - Duran Duran
10. Stay - Oingo Boingoum
11. Love Will Tear Us Apart - Joy Division
12. The Killing Moon - Echo & The Bunnymen
Disc: 2
1. Carpathian Ridge
2. The Tangent Universe
3. The Artifact And Living
4. Middlesex Times
5. Manipulated Living
6. Philosophy Of Time Travel
7. Liquid Spear Waltz
8. Gretchen Ross
9. Burn It To The Ground
10. Slipping Away
11. Rosie Darko
12. Cellar Door
13. Ensurance Trap
14. Waltz In The 4th Dimension
15. Time Travel
16. Did You Know Him?
17. Mad World
18. Mad World (Alternate Mix)