What's the biggest achievement you've ever accomplished in a video game?

[nordlead]

RolStoppable said:

I did beat all staff ghosts in F-Zero X without double taps. For those who don't know, performing side attacks during a turn let's you maintain a much higher speed while also clearing the corner at a sharper angle.

I got all platinum medals in Blast Corps. Not really hard, but again and again people have been saying that this is an impossible task.

But actually, I have to go with beating The Lost Levels on Super Mario Allstars without warp zones, i.e. all 48 levels.

EDIT: Totally forgot about my best lap PAL record on the Fire Field track of the SNES F-Zero. Converted into NTSC time it's six hundreths ahead of the next best player, therefore world record.

how in the world is time different between PAL and NTSC?

@topic

Beat Contra (NES) with my brother without either of us dieing.

Beating Super Mario Bros. while going through every stage without dieing.

Beating the dam stage in TMNT. Never did beat the game though. I must have had mad skills as a kid, as I can't get anywhere on that game now...