Hummel/Wavelength Plastic...the most consistently aggressive synth plugin I've ever heard. Basically a distortion specialist synth, but something about the ordering of components means the patches get a characterful distortion without going totally "hardstyle", and the layout makes it a pleasure to program. NiN's programmer has endorsed it (and it's a freebie so he probably meant it). Creamware only though, unfortunately.

EDIT: Ah, didn't notice you said VST only...