I'm sure I'm biased, but I'm a huge fan of how they taught our first two semesters where I went to school. Semester 1 freshman year was imperative programming in C (learning pointers, bits, the stack and heap, memory, ...). Semester 2 was functional programming in SML (learning recursion, types, function composition, formal reasoning, ...).

When it comes to other programming language features, there are few that can't be understood as some combination of imperative and functional features. Introducing them freshman year, students take these lessons with them to every subsequent language they learn.