SM57 works well for live/rough stuff. If you want to do some memorable recordings for public consumption, try to get your hands on a nice condenser mic as well. I use an Apex 460 and an Audio-Technica 4050. They both sound great, and if you mix them with a nice dynamic mic (SM57 or the Sennheiser e609 is another good one) you can get some killer tones.
Something to keep in mind: if you use more than one mic, make sure the distance from the sound source to the mic is equal otherwise you will have phase issues and the resultant recorded signal will most likely sound like ****. If you can't or don't want to do this, record each mic to a separate track, and shift them digitally later on, to sync up the signals. Sometimes small phase shifts can be pleasing (in the range of maybe 1-5ms) but anything more than that will get very ugly, very quickly.
Also: if you're using condenser mics, make sure it doesn't get too loud. They are relatively fragile and they CAN break or be ruined by extremely loud sounds. A general rule of thumb I follow is this: put your ear where the condenser mic is and play. If it's unbearably loud, chances are, it's not too great for the mic. Obviously the mic can be pushed a bit cuz it doesn't feel pain or whatever, but just keep in mind that they are not invincible and loud sounds (particularly huge, chunky, palm muting riffs) will wreck them.