Like you, I play hardcore punk with a P bass, but into a GK MB500, so fairly similar setups.
I currently use a Fuzzrocious Demon as my always on, and a Rat Tail for more distorted sections - both highly recommended, so much so I've ordered a BDPG too.
Previously, I used a Darkglass B3K - great pedal, just not 'for me' right now. Haven't sold it yet though..
I had an ODB-3 as well, didn't like it much. Had a Turbo Rat and a Gojira Heretic (Rat clone), both worked for me but the RT is far superior. Also used an MXR Bass Fuzz Deluxe and a Gojira Mammoth clone, before working out I just don't need fuzz right now (both might be up for sale soon).
I've heard good things about Sansamp Bass Drivers and VT Bass, both might be great for distortion, I want to try them out but I would like to keep my Fuzzrocious board for a few months at least!
EDIT: Also have a Bass Big Muff which I liked, especially the dry control, and it sounded great on recording, but I could never get it 'right' live.