What is the best (or as good as possible) general SVN ignore pattern to use?
There are a number of different IDE, editor, compiler, plug-in, platform, etc. specific files and some file types that "overlap" (i.e. desirable for some types projects and not for others).
There are however, a large number of file types that you just never want included in source control automatically regardless the specifics of your development environment.
The answer to this question would serve as a good starting point for any project - only requiring them to add the few environment specific items they need. It could be adapted for other Version Control Systems (VCS) as well.