What public-use license do you think is best?
For a long time I've been making tilesets, ambiance, and other stuff for Knytt Stories levels. The majority of it I release for public KS use by writing "KS use/edit OK" or similar in the image or stating the fact in a level release thread. Some of this stuff is derivative. For examples, I've created animations of Juni waking up, I've made tilesets closely based on default tilesets. These things must only be used in free Knytt Stories levels. However, much of the stuff I've made is non-derivative and there is no reason I can't release it for all public use including for-profit use.
The point is, I want to release what I can under a Creative Commons license or similar. In some cases I'll have little choice over the form of the license, because much of the audio was created from field recordings which already carried non-commercial or share-alike stipulations. But where it is solely up to me, what form of license is best? I'm thinking CC-By, which only restricts the user to giving me credit if they use my material. I'm truly unsure about share-alike clauses which require derivative works to be shared in the same way. I think SA clauses on programming snippets and libraries really make them difficult to use, but SA may not be so bad for graphics.
Any thoughts?