I have always loved the idea of AI and evolutionary algorithms. Unfortunately, as we all know, the field hasn't developed nearly as fast as expected in the early days.
What I am looking for are some examples that have the "wow" factor:
Self-directed learning systems that adapted in unexpected ways.
Game agents that were particularly dynamic and produced unexpected strategies
Symbolic representation systems that actually produced some meaningful and insightful output
Interesting emergent behavior in multiple agent systems.
Let's not get into the semantics of what defines AI. If it looks or sounds like AI, let's hear about it.
I'll go first with a story from 1997.
Dr. Adrian Thompson is trying to use genetic algorithms to create a voice recognition circuit in a FPGA. After a few thousand generations, he succeeds in having the device distinguish between "stop" and "go" voice commands. He examines the structure of the device and finds that some active logic gates are disconnected from the rest of the circuit. When he disables these supposedly useless gates, the circuit stops working...
Edit
Can we try and keep the discussion to techniques/algorithms that produced something impressive? I can google if I want to read about the thousands of AI technologies that are in the early stages but showing promise.