First post, by Nicht Sehr Gut
In the same vain as my other hopelessly unfinished lists, I'd like to create a list of PC game demos. Not just any demos, but only demos that contain "special things". Primarily, this would be things like "Half-Life: Uplink", which contains a mini-mission that doesn't exist in the actual game. But it should also include things like demos that had features that were changed in the final game and any demos with "fun" bugs.
I can't think of a PC example for that last one, but I remember in the Amiga demo for "First Samurai", there was a bug where if you jumped just right, you would land in a place where the programmers didn't intend for you to land. That would allow you to explore many other screens that you wouldn't normally be allowed to play. The closest I can think of for the PC was the "ghost" bug in "Quake 3 Arena". Amusing at first, but it got very, very annoying very quickly.
In a sense, you might consider these to be like "bonus content", but I'm mostly referring to titles where you there's no practical way of creating new content.