As much as I absolutely love the Psychotrope book (and really, how many novels out there take place in the space of exactly 12 minutes?) Psychotrope isn't really a "lone" AI, it is a collective, as portrayed in the book. A number of linked subroutines that were all programmed as psychotropic black intrusion countermeasures, which were intended to be triggered on programmers who hack their systems.
But anyway, back on topic. Another one to add to this list of insane AIs is the "TechnoCore" (Hyperion, and Fall of Hyperion), a collective AI that plans to implant all of humanity with symbionts to keep them alive so it can use their brains as processors for itself.