It's kind of hard to imagine that there are more ridiculous design ideas for Tim Burton's Superman Lives than the stuff we've already seen, including the light-up disco suit and the Nic Cage test shots. But some newly released concept art may actually beat everything.
A few of the concept designers who were working at Hasbro on designs associated with the movie have released some of their concept art. And by all accounts, as least some of this stuff may have been pretty close to how the finished movie would have looked. According to the posting at the unofficial Man of Steel Facebook group:
The designers on the development team at Hasbro Toy Group were responsible for creating designs that could be used in both the movies as well as toys. Working in conjunction with the studios, they developed concepts all the time; Ideas that could be used across both platforms. The team did hundreds of designs for Superman Lives. They also had the design team drawing Supes with cowls, masks, etc.
At the very least, this gives us some more insights into how bizarre Tim Burton's film would have been.
This is designer Ben Torres' rendering for a more "traditional" Superman suit that we would have seen Nic Cage wearing at the start of the film.
The Kryptonian Explorer suit, designed by Brian Eun, which got as far as having several sculpts done for it.
The "light-up" suit, aka the Disco Suit, that Superman would have been wearing at the end of the film. As designed by Ben Torres.
More of the Kryptonian Explorer suit, by Brian Eun.
A few random suit designs, created by Chris Samuels — unclear whether these are based on anything in the film, though.