Triggered by this question This question belongs on another site in the Stack Exchange network and the ongoing discussion of on-/off-topicness we need to agree on our main migration paths. As they appear when vote to close a question as off-topic is done, they are an important tool for community moderation, i.e. for anyone using VTC privileges.
Answers to this question should finally result in a list of possible migration paths, i.e. the most appropriate sites, the ones which we will be migrating to most often.
As always: remember not to migrate crap and being off-topic here does not mean being on-topic somewhere else.