I like the A* pathfinding algorithm. It's not particularly elegant or beautiful on itself, and it's very dependant on the heuristics applied & the topology of the terrain used. Yet the results tend to be quite pleasing to watch.
Also, it has a great website dedicated to it, with lots of interactive demos:
Also, it has a great website dedicated to it, with lots of interactive demos:
http://theory.stanford.edu/~amitp/GameProgramming/