Mausynth is a free plugin which gives you the ability to modulate Analog sounds with it's polyphonic engine.
It's a subtractive synthesizer with 32 voices and a super user friendly interface.
It really is extremely easy to make all kinds of sounds with this VST.
Almost any music genre can benefit from this one if you ask me.
Plus the sound quality is top notch, so you can't really go wrong with this.