Inspiration for this thread came from the "What was the First Console you ever Owned?" and "What was the first game you ever played?".
First game I ever beat was the Super Mario All-Star Version of Super Mario Bros 2. It was cake with Luigi and his shakely long Jumps. Because of this Super Mario Bros. 2 will always be my fave OG Mario game and hold a special place in my heart.
And the rest of you?
Edit: I was 7 or 8 Years old to when I did it as well.