Lambda The Ultimate Goto #78
Description
By Guy Steele and Gerald Sussman
http://repository.readscheme.org/ftp/papers/ai-lab-pubs/AIM-443.pdf
All the Lambda the Ultimate papers are great, but this one is (a) the most stand-alone and (b) the most generally useful, I feel. Plus it's the paper that invented tail-recursion and still explains it better than pretty much anybody else!