I made this yesterday because I needed a freaking awesome logo for my Pokemon Diamond and Pearl Walkthrough that's hosted on GameFAQs (and some other places). Took over 4 hours to finish. I used Adobe Photoshop to supply the background of the image as reference for ASCII tracing, and then let 'er rip. This was done strictly through Adobe Photoshop (for mapping the lineart) and NoteTab Pro (for everything else), and not through a ASCII art program like JavE (which I found when I was 95% done and I'm like "skip this" because I was practically done anyway).
I'm quite surprised that I managed to do this well. I don't usually do really big complex ASCII art like this.
Image is from the box of Pokemon Diamond, which I own and scanned myself. Har har.