[synthsonix]

I reckon a simple saw wave, doubled up with the sub osc to beef it under, and then getting the settings right with the Filt Env is crucial. You can give the sound an almost percussive, punch quality with the filter decay.
Sometimes also adding a tiny bit of envelope pitch through the Filter Env can also add a bite to the sound.

And then, quite important I find is running it all through the right filter saturation mode... Medium is always good, but you can always push the input
to add some more interesting overtones to that filtered bass sound.