Experiment with different filter types, routings and combinations. Very important. Try wobbling a high pass around 200hz with -0.30 amount and an unsynced rate. Then, route this through filter 2 which can be a low pass to remove those really high harmonics that you don't want in a bass sound.
Try different wave forms for your oscillators. A square is a square. An apple is an apple. Wavetable and FM synths are going to give you more interesting, and in turn grimier results.
I find it good to have a synthesizer workflow. First, make your initial sound, and as gritty as you want it, and really play with all settings and try modulations and stuff. Then, set up your filters how you want them and maybe add the wob wob. Then, set up your FX chain. Delay, reverb, chorus, and of course distortion are all good options.
If you have MIDI knobs, set them up. Automation will make a boring sound brilliant. Again, experiment!
One last thing, a good bass needs sub. Use an instrument rack in Ableton or program your synth (for example Massive has Oscillator Bypass) to make sure that you have a nicely tuned sub channel that hits with your bass. Also, experiment with leaving some midrange (above bass where you stop feeling and it and start hearing it) for a fuller mix.
