Yep, this is for the moments in your video gaming history that you can look back on and think, "Whoa, it's so awesome, I actually accomplished that!"
For me, it was defeating the two optional bosses in Final Fantasy VII - which took endless amounts of trial and error until I finally toppled the underwater one first, and then the one in the sand a couple of months later.
Of course, 100% completion on Vice City also gave me nice bragging rights. I don't ever want to do the dirt bike arena mini-game EVER again, though.
And actually passing "The Legend of Maxx" on it's full 10-foot glory - never mind that I didn't pass it well, just the fact that I passed it is enough to give me pride.
So, what were the moments that did it for you?