We've all had those moments: if coding was a spectator sport, the crowd would be cheering you on, and going wild when you score the goal / touchdown / try in the last seconds of the game.
This question is the opposite of the Confessions of your worst WTF. It's your chance to show off, and talk about your heroics to people that understand. That moment when you saved the day, and fixed the bug that was costing millions of pounds a day, or five previous developers couldn't fix it, or, like Harrison Ford, you attached a fax roller to an iPod and took a video screen shot of scrolling text.
It may be a small heroic that nobody else noticed, but you know, without doubt that you saved the day. Nobody else would understand, or even believe you, but you know. You know.