Someone earlier mentioned Numerology, and I heartily concur. While it’s sample mangling potential might not be obvious at first glance things can get pretty crazy when you consider that every perimeter of the built in sampler player can be modulated by the step sequencers. Here’s something I threw together in 5 mins, it’s crap but hopefully it demonstrates the kind of controlled chaos Numerology can provide.
http://modularsamples.com/loopmolester.mp3
Also, Metasynth can do some incredible things with samples, stuff I’ve never heard elsewhere.