I often use this recipe as an alternative to a graham cracker crust. It's very crumbly, tastes like a buttery oatmeal cookie, and has a nice salty and sweet thing going on which is a great contrast to most sweet fillings. Use it whenever recipes call for a graham cracker crust.
'graham cracker crust' on Serious Eats
Key limes can be a bit hard to come by, but this recipe for Key Lime (Or Not) Pie from Mrs. Rowe's Little Book of Southern Pies by Mollie Cox Bryan is forgiving. You can substitute fresh lime juice for Key lime juice and end up with a pie that is equally delicious. Topped with a dollop of fresh whipped cream, key lime (or just plain old lime) pie is unbeatable.