Maybe if you had an HD4 it would of sounded better.. (sorry had to)..

57's can work well on amps. Very standard mic choice of electric gitters.
What kind of guitar/amp are you using? That will have the biggest effect on your sound..

I doubt the 57 is the source of your problem, you may not prefer it, but it can be found in any "pro" studio anywhere and for good reason. Again it may not yield the tone you want, but I have found that as important as mic placement is, the chain before and after the mic is equally as important. Maybe you don't like the amp you're using? How about the preamp the mic is running through? EQ?
Ideally you should be able to pair the 57 with a good preamp and setup the guitar amp with good eq settings and place the 57 in a good spot and get an awesome tone. But there are a lot of variables, maybe its even your room, is it treated? Does it have a good reverb to it? Depending on style, you might want it to be as dead as possible.
I also find my amp settings are completely different playing live as opposed to recording. Usually I end up rolling out a lot of the low end on my amp and making it brighter than I would just sitting in a room with it. Also you will probably find for distorted guitar you need much less distortion than you think to punch thru a mix.
As eRic suggests, you may want to try stacking a DI plugin with your source mic, I almost always use two sources per track as well, whether it's two mics, one moc and a DI or two DI tracks with different amp sims. If I need heavier distortion or drive I'll have one channel with very little distortion and more mids underneath the distorted track to bring out some transients and punch. Maybe try sticking the NTK in front and the 57 in back or both in fron ton different speakers (be careful of your phase though if they're both close mic'd)

Give us some more info about the style and sound you're shooting for, about your gear and about your room, we could probably get you more specific info.

word.

I use a combination of mics on guitar cabinets. It really always depends on the tone I'm looking for. But my pair of Royer R121's are nearly always involved, both in front of and behind the cab. And a 57 is often involved, too, although I tend to go for a 421 or 441 or a Blue 8-Ball first.