Something to read while I finish the rest of the concept off.
GLaDOS from Valve's 'Portal' is probably the best example of a psychotic A.I. ever!
Portal 2 is out soon, which you all will know already.
You might also know that Valve is offering a great deal for loads of indie games with a pre-order of Portal 2.
Also, that if you play a sort of Portal easter egg in any or all of these games it adds points to an online table that, once filled, might release Portal 2 sooner. Its a bit late now to bother for that but the easter eggs are pretty cool.
Here's one that uses GLaDOS's trademark voice in an awesome little game called Audiosurf.
It's something similar to this that I want for Glitch's Computer.