Handhend Nintendo 64 (Nicknamed the Retro64!)
Gathering information from www.forums.benheck.com (of which I am a member) I build a Nintendo64 portable. :D N64 is my favorite system, and I figured it'd provide an interesting challenge. I decided to make it the smallest while I'm at it, and this N64 portable is currently the smallest ever made.
You can see the News topic here, (has much more pictures) and the 22-page WIP topic here.
Just so you know in advance, I am not making an Instructable for this one. There is tons of information in the N64 section at the forums, and the N64's board is extremely well-labeled anyway.