My favorite 1v1 fights in the MA is F6F vs. Just about any plane.  Why?  Well, aside from being a big fan of the Hellcat, I find it to be very versatile.  I can BnZ the Zekes and I can TnB the Ponies.  It gives me a challenge because it forces me to use the strengths of my plane vs. the strengths of whatever plane I am fighting against.  Usually, the fight boils down to who makes the mistake first (which, usually, is me) of trying to fight the other guy's type of fight.
-math