This Line 6 M9 is a great sounding unit. It is an effects modeler, and it is meant to run in front of an amp, just any other guitar pedals. It has tons of effects in it, over 120 of them, and I think they sound kick ass good.
I made some demos of the M9, so that you can get an idea of what sounds this unit is capable of. The distortion sounds get criticized, but I think they are totally usable.
The Rabid Rodent is a distortion pedal built my friend Bob at www.duhvoodooman.com. It is more or less a copy of the classic Proco RAT distortion pedal, but the Rabid Rodent has a lot more tonal options.
In this demo, I am playing a Michael Kelly Patriot Shadow, which has high output humbuckers in it. The amp I am using is a 4 watt GEM amp from http://www.mackamps.com . I did not use any other effects used in this video. The volume of the amp on this volume was very low, to avoid clipping on the camera microphone. I stunned at how good this setup sounds! I can get tone close to those of a Marshall stack, but without the ear splitting volume. I highly recommend this pedal if you are looking for a great and versatile distortion pedal. I also use it for blues. You get such a fat tone out of this pedal, and with single coils and low gain on the pedal, a sweet blues tone can be had.