I know you posted this in the Lounge, but I got to it via the "New Posts" topic, and I'm actually dissappointed you aren't talking about extreme fish foods that will cause colors to pop or something like that.
As for extreme people food, well I know a couple of Korean joints that serve that. I also know a Pizza place that has a double Jalapeno pizza that's kinda extreme. At work we use it to break in new workgroup members. If they can consume a slice without doubling over, we figure it's worth training them.