This is going to sound sad. Horribly sad.
Dreamcast, Sonic Adventure. Skip to the 1:00 mark or so, where he gets the shoes. Now, about twenty seconds after that, where there's the trail of rings?
At age 7ish, I got stuck on that. I spent days trying to figure it out, before finally giving up. Three years passed before I got back to it. Another three before I went back to it again, finished Big's story mode (stupid fishing minigame...) and beat the entire game. Stupid, I know. Not sure how I failed to get that.