I use D'Addario phosphor bronze medium-gauge guitar strings on my Martin D-18, and am never disappointed. I also use the light-gauge strings, both phosphor bronze and 80/20, for some of my other guitars. They can be counted on for clarity and brilliance of tone. For my fiddle, I like Helicore heavy-gauge violin strings, and for my string bass, I use Helicore as well.
And my banjo loves D'Addario as well! D'Addario mini headstock tuners are my favorites. They are inconspicuous and easy to use and read.