All Star Superman » All Star Superman #2 - Superman's Forbidden Room released by DC Comics on February 2006.
There are some wild ideas here, and a tour of the super fortress is just pure, insane fun (especially the future Supermen!), but Morrison's Lois Lane is really quite awful, and the issue revolves around her as much as it does Superman. Paranoid, disinterested, bratty -- why? Why did he rewrite Lois Lane as a 15-year old, and an unpleasant one at that?
Wait, I thought the Fortress of Solitude was made of giant crystals and stuff? In this it's basically the Batcave. Ah, whatever. After finally revealing his secret identity to Lois, ol Supes shows her the Supercave (c'mon, that's what it is, basically. It even has a giant penny with the Joker on it. Sure, Batman's giant penny just has Lincoln on it, but really, why does Superman have one? And with the Joker on it of all people?) Anyway, Superman shows off his robot butlers, his laboratory, his ...