Basic and delicious.
1 1/4 cup crushed graham crackers (used to be one sleeve of Honey Maid's, until the scammers shrunk the package, but not the box. Now you'll need to rob 2 or 3 crackers from 2nd sleeve)
1/2 stick of unsalted butter, melted
1/3 cup brown sugar
Mix well and put in pie dish and form crust evenly up to the edges of the pan. Bake in pre-heated oven at 350 degrees for 12 minutes. Let crust cool 15 minutes. Meanwhile ...
Whisk well in bowl:
2 1/2 cups sweetened condensed milk (2 cans)
2/3 cup freshly squeezed key limes ... add another ounce or two if you like it extra tart.
4 large egg yolks
Pour key lime mixture over pie crust and bake 10 minutes at 350 degree.
Chill, preferably overnight. Serve w/ whipped cream
ETA: I prefer crushing my graham crackers with a pestle. It lends a rustic/artisanal flair.