Oh, I love
Cleo! It's quite versatile -- I envision both a reserved, bookish brunette and a jaunty, vivacious redhead (just to mention two characterizations) when I think of the name. I do prefer
Clio, though, because I enjoy the gravitas that the elevated classical association (Greek muse of history) lends the name.
I vastly prefer both
Cleo and
Clio to
Chloe, which needs to be put to rest.