For me its Sonic 1, 2, 3 etc and all the Mario games ever made. I was born in the times where I grew up with the nes/snes and master system/megadrive and I never once even got close to finishing some of the most well known games on the sytems. It wasn't due to a lack of time or interest but simply how much I really couldn't do it - I just wasnt good enough. Hell even recently I tried sonic 2 again and I still get stuck in the exact same place I did years ago. I still suck at these games and feel like I really should have the ability to finish them. Any game you've never completed yet it seems everyone else in the world has?