My favorite mics for guitar?
I'll be honest, I use pretty much anything and everything, from a u67 to a Radio Shack piezo, depending on what I need, but my go to's include:
Shure SM-57 (obviously)
Shure KSM-313 (Ribbon, I usually prefer it to the Royer, a bit brighter and more characterful, can handle high SPL's better)
Shure SM-7b (a bit smoother than the '57)
Shure KSM-44a (my go-to LDC for guitars - quiet, basically uncolored)
Josephson c42 (my go-to SDC for clean tones)
Beyerdynamic m201 (one of my go-to dynamics, especially when tracking "live" - flatter than most)
Beyerdynamic m160 (my favorite ribbon on guitars - hey, if it worked for Hendrix...)
Audix i5 (brighter and clearer than a '57, works great with "aggressive" sounds)
Blue ENcore 100i (another alternate for the '57 - a bit "woodier", pretty similar to the m201)
Electro-Voice 635a (go-to for mid-gain tones - omni dynamic, very good at "feel", and not quite as detailed - no need to use a HPF, no proximity effect)
Heil PR-30 (go-to for single-mic applications - can be a bit strident at times, but has a response that is generally closer to a ribbon than a '57)
Royer 121 (I'll be honest, I don't pull mine out all that often, but it does what it does well)