I keep feeling like someone must have invented this one before - it just seems a little too easy. But it's also damned good, and it's proven a surprisingly flexible formula. Anyway, I'll take credit for naming it (based on the colors of its three main flavoring agents).
2 oz Laird's Applejack
1/3 oz green Chartreuse
1/3 oz Cocchi Americano (Lillet Blanc could work, if supplemented with a dash of orange bitters)
1/3 oz Aperol (or Campari, in a pinch)
Stir over rocks and strain over one large ice cube in a rocks glass. Squeeze an orange peel over the top and discard.
I list applejack here only because it's my favorite variation so far. Like the Pirate, this lends itself to easy substitution. I've tried it with rye, bourbon, and genever, all of them successfully. I haven't used brandy or an aged tequila yet, but I'm sure these could be good options too. Rum, not so much, but you could give it a whirl.