I think RJD2, Dj Shadow, Madlib and Pete Rock. When you listen to some of Shadows and RJD2's, its genuinely hard to imagine that those sounds weren't together in the first place, but in reality they've been taken from so many different sources.....And most importantly they're not just taking looping a two bar section of music, they're layering, chopping and constructing everything from existing pieces of music and meshing sounds together etc. [as opposed to using a single sample, and adding some drum sounds]