Well I think Google is a better choice than FB, but I can't think of any services I use where one or both of those are the only options and email signup isn't.

Well I think Google is a better choice than FB, but I can't think of any services I use where one or both of those are the only options and email signup isn't. The only one that comes to mind (and that annoyed me the other day) is ProductHunt, which has 4 options for signup, but not email.