Free Plugin: Saturation Knob by Softube
This guy does one thing and does it f$#%ing well. SATURATION. Use it subtly to add a little grit to vocals, or crank it to drive the top end of your live bass tracks so it cuts in the mix. It has a small LED that lights up as you start hitting the saturation - so you can really find a sweet spot that works. There are also 3 saturation types (Keep High, Neutral, Keep Low) - you really have to get to know their character to be able to use this thing. Highly recommend this one for squeezing a little more balls out of your digital synths as well.
The lush synth days are so 2014...get with the times and grit your stuff up!
Download it here for free.