Who doesn't like code. I prefer that over Super any day
I don't like Code because it doesn't make any sense.
Super is cool: that key is called Super on all *nix systems, and Super is a widely understood term for the key.
System is even cooler: the key performs a system-specific action.
Meta is also alright because of Emacs stuff. It's also equally as short as Code, and arguably better because you don't get two C's in a row (
Control,
Code).
Windows logos are not okay but still make sense.
Code makes no sense: the legend was taken from electric typewriters, where the key performed a function much more similar to Shift than to Super.