While we're on the subject: Budiansky named Megatron, but not Optimus Prime.Denny O'Neil named Optimus Prime.
(EDIT: Better link; now goes to a Comic Book Legends Revealed column instead of a line on O'Neil's Wikipedia page.)
Those of you who are comics fans know who O'Neil is. Those of you who aren't may not, but you've seen his work in some form or another. O'Neil and artist Neal Adams are probably the most celebrated Batman team of the 1970s, and created Talia and Ra's al Ghul. They also did Green Lantern/Green Arrow, which is still largely considered the high-water mark for both characters and is best remembered for its social conscience. It was often clumsy -- I believe it was Chris Sims who described it as a series about how Green Lantern didn't know racism existed
and Green Arrow didn't know drugs existed
-- but that they were even trying
in a DC comic was a pretty big deal back then.