I like to try new fonts from time to time, and Typographica's annual Favorite Fonts essay is always a nice opportunity for a little font shopping.
A new font that works nicely in Tinderbox maps is Proxima Nova.
When I first posted this, I wrote Proxima Sans. Michael Newman swiftly caught the blunder. Yes, I mean Proxima Nova, SImonson's 2005 font, and not the older Proxima Sans. But, if you're on a budget, Proxima Sans might be a good substitute.
Kyle Hildebrant says, "It nestles neatly in a place between the geometric, grotesque, and gothic." It's clean, fresh, and legible.