SevenString.org - View Single Post - SM57 sounds good only at the super edge?
Link to the post with audio clips - tl;dr on the rest of the thread, guy was unhappy with his recorded tone using a SM57, posted looking for some tips over at Sevenstring, and (god only knows why this occurred to him to try within the first couple days), ended up just renting a second SM57 to make sure something wasn't wrong with his mic. He then posted these A/B clips, ecstatic by how much better the new one sounded - turns out, his was a fake.
So, he inadvertently recorded an awesome comparison of the differences between a real SM57 and a fake one - the riffing is even pretty good.
What a difference!