I LOVE key lime pie. Here is the easiest recipe ever, and it makes a great pie.
Five egg yolks
1 can of sweetened condensed milk
1/2 Cup Key Lime Juice
Graham cracker crust
That's all there is. Just beat the egg yolks and then add the sweetened condensed milk and lime juice. Beat it well and then poor the mixture into a graham cracker crust. Bake at 350 degrees for 15 minutes, and you're done. It literally takes longer to go to the store to buy the ingredients than it does to prepare it. You can also add whipped cream or lime slices when serving, but it's great plain too.