The second most popular guitar-speaker mic is probably the Sennheiser MD-421. It has a beefier tone than the 57, but not as much cut. Good alternative sound, but it's quite expensive. I've heard that the Audix OM-2 is really good, but I've never used it myself. I've used the Sennheiser Evolution series (is that what it's called?), the flat one that sits flush against the grillcloth, and that sounded great on a Recto cab. AKG C1000 will give you lots of treble and sizzle. Not a bad mic, especially if you have a dark sounding amp/speaker.