I qte like the Boss Flanger sound... am waiting to be able to get it. Generally, I like Boss pedals and practically all I use are Boss, except for an Ibanez TM5, the Crybaby Wah and a DOD Octaver.
The ones I have are the CH2 chorus, TR2 tremelo, DD3 delay, OD2 overdrive which are basic sounds/effects. I used to use the Boss ME-10 (yeah it's old, but has nice flanging and phaser sounds) as a complement to my stomp boxes. Had an old DS, but didn't like the sound.
So far they seem to work pretty well with my setup, altho as I said, I'd like a Flanger or Phaser, or even a booster pedal like Ibanez Tubescreamer. Not too sure about the BLues Driver tho...