So far the best bass pedal I've tried/used/owned is the Sansamp Bass Driver DI (BDDI).
I debated getting a Bass Fly Rig, but I'd need to do a good comparison. Two things prompted me to consider it: 1. my chorus pedal seems to have stopped working, 2. I've been tidying up my pedalboard and that seemed to offer a neat solution.
I have a VT Bass pedal and it's OK.
I tried the YYZ and liked it, but it's pricey and I don't necessarily want to sound just like Geddy Lee.