I've only ever owned one phaser, but the Red Witch Moon Deluxe is 1) versatile with it's 6 way selector, and 2) very natural sounding. They have some settings that combine phase and tremolo that I REALLY like. The pedal also does tremolo on its own, but it's very subtle and I don't use it much.
Check out the Pfeiffer phaser. I think you can only get them from proguitarshop.com. Its a three knob phase and can even do some envelope filter sounds do to the feedback control. It sounds amazingly good and for $130 brand new I guarantee you won't find a better sounding or quality phaser. Yes its true bypass.
one phaser to rule them all... modfactor ...if you're counting digital devices
pick a type neg, positive, biphase, feedback... pick how many stages, add a 2nd lfo, pick any waveform, or sweep it with expression pedal, sample and hold sounds like a step filter, tap tempo...
i'd get it if nothing else just because it will let you try out different types and if you don't like it sell it and you'll get enough back to pick out whatever one or two trick phaser you like most...
if you're only counting analog i liked the option 5 destination phase, which i believe is a feedback type 4 stage with optical components, lfo can go real slow and it's stereo so it sounds cool as a doubler
i think most of these listed are 4 stage feedback phasers? phase 90 and small stone are i believe
modfactor setting i use most is a positive 4 stage set for a vibe like sound
Then you need to try the Retro-Sonic Phaser. True Bypass, warm, 100% analog. It has a trimpot in the back that you can use to adjust the phasing.
Well built, great sounds, and while it is supposed to be exact replica of the vintage '74 MXR phase (I believe), I think this one sounds a bit warmer. Just don't expect to get crazy phasing out of this one. This one is more about subtlety and warmth...