I'm a phaser nut and have tried many of them, though not all.
My favorite for bass has always been the Maestro PS-1a, here's what it looks like (with the incredibly rare footswitch, not mine)...
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Here's what it sounds like on one of my tracks, pure juice...
It is not a true bypass box and it has almost no tweakability though you can get under the hood for some things. It also rolls off the high end noticeably, yet there is an aliveness to the modulation that nothing else has been able to get.
I had an HBE Psilocybe on my board for awhile because I was tired of taking the Maestro out of the studio and while I think it's a great pedal in it's own right it only got 80% of the way there to the Maestro bubbliness (better than the other modern pedals I've tried).
Another fantastic vintage pedal is the Mutron Phasor I (not the the II !). Pure bubbly goodness with a nice alive factor that rivals the Maestro.
I sold mine for the Phasor II because I figured it would sound the same but had more control over the sound. Big mistake, they don't sound the same at all. Still, the II is better than almost anything out there now IMO.