Class Job Change in Final Fantasy IV.
This one disappointed me. He went form bad ass Dark Knight to pretty boy blue eyed Paladin. At the very least he finally looked like a Cecil.
I'd have to take a while to recall some memorable gaming moments from my childhood since that's where most of them will probably be hiding.
Off the top of my head I'd say:
Realizing that I now have my own castle in Suikoden.
The Suikoden 2 opening with all the familiar faces (Lets just say I was pretty excited about finally getting my hands on that game).
Watching the Soul Blade intro, at the time it was pretty amazing.