MXR have been knocking it out of the park lately with their "Bass Innovations" line. The Bass Comp, Bass Envelope Filter, and Bass Distortion are all killer pedals.
EHX are easily the most innovative and experimental of the mainstream builders, IMHO (well, I suppose one could make a good argument for Digitech, or even Zoom, but EHX tend to capture my imagination more).
Boss should get at least an honorable mention for pedals both celebrated (Octave, Flanger) and underrated (Phaser, Bass OD).
I've only owned one pedal apiece by any of the smaller, "boutique" builders I have any experience with, so I don't feel terribly qualified to speak on them. But I have to say that Earthquaker really have my attention for all their wild and wacky pedals. It seems like a lot of boutique builders either focus on cloning discontinued pedals, or improving on existing circuits. I guess you could say the same thing about mainstream builders too. While I have no real experience with Earthquaker, I have to admire what they're doing a whole lot.
I've also had the pleasure of trying several IdiotBox offerings in person. They definitely deserve an honorable mention for their gnarly dirt pedals! One of them is so gnarly they had to put a picture of Jeff Spicoli on it.
