Neither, they are both boring, get a life, then if you have any time to spare, come here.

I don't see much of an upside to either based on non belief. If youre trying to stay among likeminds this site is better than both. If youre trying to keep up with pop culture and breaking news, twitter. If you're trying to keep up with friends and family, facebook. If youre looking for memes and to debate, fb groups. If you're looking for memes and one liners/mini debate clapbacks, twitter. If you're looking for where everyone went when their parents joined FB and twitter, probably instagram and twitch.