I like skip lists (technically a data structure, but with associated algorithms). I love the simplicity vs. other balanced tree algorithms. Also I'm a fan bec

I like skip lists (technically a data structure, but with associated algorithms). I love the simplicity vs. other balanced tree algorithms. Also I'm a fan because it's a relatively recent development that shows that progress is still possible in fundamental areas. https://en.wikipedia.org/wiki/Skip_list https://en.wikipedia.org/wiki/Skip_list Some runners up: Gosling's dynamic programming algorithm for optimizing text editor screen updates and gap buffers.