My earliest gaming memory is being terrified of Dr. Robotnik....In GREEN HILL ZONE. I think it was the music that set me off.
On my first playthrough of Pokemon Red, I deleted Charizard's Flamethrower for Fire Spin.
I used a P-Wing in the first Mario 3 fortress with the Boos because the Princess mentioned ghosts in her letter, and gave me the item, so I thought I had to use it where there were ghosts. Then I flew into a Thwomp. :(
I found a cool retro-gaming websito called "Retro-Sanctuary".
He's done lists for NES, SNES, and Megadrive, and even more recent consoles like Gamecube and Dreamcast.
Check 'em out; maybe you'll find an overlooked gem.