Everyone shitting themselves when Super Saiyan Gohan powered-up to fight Cell.
The main reason why isn't because of the reactions alone, but also because that was when I finally realized Gohan was superior to Goku. Long before I read the Manga, I just assumed Goku was the more powerful one based on the way he fought Cell in comparison to Gohan. I was also a bit of a Goku fanboy who always wanted to believe he was above everyone else, so the idea of a kid that didn't have Super Saiyan nearly as long annoyed me. It wasn't until someone pointed me towards this particular chapter that my perspective began to shift as I continue to immerse myself in the Manga.