I am uncomfotable with the idea of "best" or even "first" choice. I'll give you an example, on a recent CD project of west african palm wine music (acoutis guitar oriented world folk), i had four players: two acoustic guitars, acoustic bass and percusion, all in the same room. each guitar was miced with 2 mics. we used a total of 7 difference acoustic guitars on the 10 song project. I think i used around 10 different microphone models, mostly SDC, sometimes LDC. Almost always, a KM54 was involved, but mosly we listened to the song, selected which guitar based on listening to the song (sometimes we'd do a recrding then decide we wanted a different guitar), then i'd select mic based on song and guitar. the point i wish to make is that there is no "first choice". I select mics based on what is available and what the specific application is demanding that i use. thus, even with only one guitar, i am likely to use a different microphone on different songs- or not, depending on what i am hearing and what i am trying to achieve.
Another way to say this is: once you've bought your "first choice", you'll immediately start shopping around for your next "first choice".