There are plenty of tiny companies making weird, interesting VST instruments for very little money. But one of the weirdest and most interesting is NUSofting. While big companies are producing endless retro-influenced synths, they invented Peti, which is a harmonium and accordion simulator, and Harp Time, which is (obviously) a harp simulator. There are free demos of both on the site.
Their new one is Microrock, which looks like a guitar amp and sounds like a guitar being fed through loads of distortion and effects. But it's a mono synth, so don't expect it to actually sound like a guitar.
Essentially, it makes all the noises that Liam Howlett should have used on the new Prodigy album. But didn't.