First, be sure that the question isn't grounded in any kind of objective problem that could receive concise, verifiable answers. The issue with these types of questions is that they can go on forever due to the scope being poorly defined. Sometimes new users give us great questions that are just asked less than ideally. If it's clear that the question could be edited to be of a much narrower scope, consider doing so.
If not, overly broad questions should be closed quickly because ironically they tend to receive quite a few answers, creating a sort of perennial distraction on the front page of the site. There's several closing criteria to choose from, but they all basically point to the question being fundamentally off topic for the site.
You can choose to recommend that the question be migrated to a site within our migration path, but please do not vote to do so unless you feel that the question is excellent, just asked in the wrong place. It's not required, but editing to fix any grammatical / spelling / formatting issues in a question prior to migrating it is always appreciated. We're the flagship site of the network and we're notorious for migrating ... not so great questions, which is something that we really should be mindful of. In other words, don't just shift junk from our yard to another. Don't migrate crap.
If the site you have in mind is not in our migration path, you can flag the question as 'other' and let us know where you think it should go. If you do this, please tell us why you think the question is fantastic, at least to the point that you can in the flag dialog. We (moderators) don't usually migrate a question outside of the available paths without a compelling reason, especially to beta sites.