I don't like any because they all make me think of something bad.
Purity makes me think of little girls that turn slutty just to live past their name.
Chastity reminds me of the same thing, but also chastity belts.
Pristine reminds me of a girl who is constantly fixing her hair and makeup.
These names could only work in a certain time period I think, when these were actually virtues that everyone admired in a person. Nowadays they don't seem to be taken seriously, and people with these names may well be made fun of. I do like the idea of them though...just not for today.