That's a pretty general question. :)

Lots of VST instruments out there.

But if you're just craving DIY FSU, it's hard to beat good ol' ring mod. Multiply anything by anything else, and you've usually got some type of tasty mess. (The richer and more inharmonic the sources, the messier the product.)

If you're into glitchy sounds, well, pretty much anything short and ugly will do, especially the ridiculously high or low.

yeah, I'm realizing that I was very vague in my request. I'm really digging these though, so thanks :)

I'm a modular synth dude (as I believe you are, as well?), so I'm trying to move beyond the analogue-style synthesis, and I just remember hearing some really interesting "digital-style" synthesis.

I guess I mean digitally glitchy; sidebanding, chopped, bit-reduced clunky stuff. It seems everything I cook up with wave~ and such ends up being really fizzy and not really exciting to my ears :-/

thanks.