Caspa and Rusko are both huge names in the dubstep scene on their own, yet have collaborated in various releases, and also frequently DJ together. Their mix for Fabric, Fabriclive. 37 is considered to be one of their best collaborations.
FYI, Fabriclive 37 is a COMPILATION album. Credit should be given to the proper producers as only 15 tracks on this 29 track album are from Caspa / Rusko. Many of you know this but many people also don't. Personally my favorite two tracks, Forever & Rainbow Tear Drops are from ConQuest and Orien.