hard to limit to just 3. But I might as well choose my primary bass-dedicated pedals:
EBS multi-comp (#1 for sure in my list of priorities)... always on.
I have to include my behringer bass v-amp pro with the behringer foot controller for the following effects:
- drive control (once you work out how to get to it through various shift-presses as it's unlabeled and undocumented)... one day I'll get a pedal that is as good as this giant rack and board combination just to get my grind... but for now this is what I use as it sounds better than anything else I've tried so far.
- amp sims and cab effects (really good, on those rare times when I need/want them considering I already play through an amp and cab)
- recording and di along with before-amp capabilities (I use it before amp, in other words without cab sims, most of the time)
- mu-tron envelope filter (the v-amp one is outstanding)
- octaver
BOSS oc-2 octaver (great octave and 2 octave down pedal, much more synthetic sounding than the v-amp, a nice change)
If I were to go to 4 pedals, the only other bass specific pedal I own is a behringer bdi-21. Such a great pedal, but not useful to me as it has undefeatable cab sims and I actually need to go into my amp, through it's tone stack, and through my own cab for most of my work. But it's been the greatest live sound secret I've ever had. I personally mildly prefer it's tone and particular settings I can get out of it to the real thing of which it was a knock off.
If I were to go to 5 pedals, it would include my zoom G3, the guitar version. It has great modulation, delay, pitch, and much more audible in-your-face compressor effects compared to my ebs that come in handy all the time.... it's always in my bass chain, although typically with all effects turned off.