Mary is definitely less common today than it has ever been, but it still feels very default and ubiquitous. I would not want to be named Mary at all. The one really good thing about it is that it goes very well with lots of middle names, and sounds good as a double-barreled name too.
Mary Amber
Mary Bliss (only throwing this one out because it's the main character in "Little Bitty Lies" which is a very fluffy but very good book)
Mary Carla
Mary Dawn
Mary Ellen (I really like Ellen)
Mary Fern
Mary Giselle
Mary Heather
Mary Jessica
Mary Kathleen
Mary Lucia
Mary Natasha
Mary Opal
Mary Portia
Mary Robin
Mary Sky
Mary Tanya
Mary Vanessa
Mary Yasmine
I think, therefore I judge.