I grew up with a Margaret Ruth, nicknamed Maggie. As much as I like the name (not Maggie), the girl grew up to be one of those rich ditsy girls I can't stand. I associated Maggie more with her though since that's what we always called her so the nickname Maggie brings a terrible impression to me. I'd use Meg, because Maggie will always make me think of her. Or a dog, since there was this book I read with a Newfoundland named Maggie when I was little. Strangely I really like it on a dog.