My bass board for live use consists of the following things:
Planet Waves Tru-Strobe Pedal Tuner > MXR Custom Comp > MXR Bass DI+
I used to have an MXR Classic Overdrive (just a Tubescreamer clone), but it sucked way too much low-end out, so I just went back to the essentials. It gets me a pretty good tone when I run it thru my amp and the two channels of the BDI+ give me lots of versatility. It's also go the DI out if I wanna go straight into the PA (the distortion channel doesn't sound all that great straight into the PA, tho). The compressor is on all the time just because it just makes things sound plain better, lol.
I would LOVE to try a VT Bass... and I would also like to incorporate a second, more tweakable compressor (like the EBS MultiComp or the MXR Bass Compressor) somewhere in the signal for some added fine-tuning of dynamics.
Some sort of Fuzz would also be nice, actually. I'd love some sort of Woolly Mammoth clone.