Heh, funny this should be brought up - the other day, I just uploaded to YT a short segment of that scene; specifically, the 30-second clip where "It" reveals the cure for the Hate Plague.
https://www.youtube.com/watch?v=D5hfVC93KEU
And yeah, Return of Optimus Prime is special to me, too; having missed Optimus after his death (even though I could still see him in re-runs), I remember being particularly existed, because the two-parter aired just mere days before my birthday.