i love an AKG c414 b-uls on accoustic guitars,
connected to a joemeek preamp,
gives me great results,and i heard a few other people say the same kida thing
its a pretty 'expensive' mic, but for me its worth every cent i payd for it !
for the rest i used an NT3 - stereo pair, nice results but didn't really impress me, an NT1 is clean, but once again didn't impress me alot
if you record guitar, and you are willing to spend some money,
then i'd go for two mics, and a dual channel preamp (like
the Joemeek twinQ for example (around $700 i think).
this way you can try to record in stereo, and might come in handy if you want to record overheads for drums or no matter what other thing that needs a natural sound.
so in short, my choice would be:
1 (or two if you can afford it) akg c414 (around $800 a piece) + joemeek twinq (around $800)
http://i21.ebayimg.com/02/i/02/ad/33/3d_1.JPG
or if you want it alot cheaper,
2 rode NT3's ($170 a piece), as a preamp, once again, i'd go look around in the (cheaper) joemeek stuff (cause i love that sound)
cheers
two ro