Eddie Your Shipboard Computer

In the third episode of "The Hitchhiker's Guide to the Galaxy," Ford Prefect disputes Zaphod Beeblebrox's claim of them being in orbit around the legendary planet of Magrathea. Zaphod then asks Eddie the shipboard computer to confirm this claim, much to the chagrin of Ford, who can't stand the computer's ridiculously cheery personality, and wouldn't trust it to even spoke his weight.

Example of:
Cheerful A.I.