Crunchyroll has a good selection, and most importantly is legal. Free with ads. (I'm a premium member because I watch anime exclusively. I'm one of those kinds of people.) It specializes in subbed anime.
Funimation's streaming service has free stuff as well, though I don't use them very often. They specialize in dubs. (Probably why I don't use them, since i prefer subs.) Oh, they are also legal.
I would discourage any illegal sites, even if they host something rare. On principle, but also because they tend to become virus hubs. Among other things.
*edit: when I say, "legal" I'm more specifically meaning the site got proper permission to display the content, indicating the people responsible for creating the content are getting paid for their work in some way. Also, legal sites generate revenue off of their reputations, which is a strong motivational factor to keep malware out of their product.
Last edited by Rusty Claymore
on Thu Sep 15, 2016 1:51 pm, edited 1 time in total.