I really like
Christina. To me it doesn't seem stylish or hip, but that doesn't matter too much. It's a classic.
Christy ruins it though.
I prefer
Christina, I HATE
Crystal, and I like
Christine, but not as much as
Christina.
I wouldn't use
Christina, but I don't think it's because I'm not a
Christian. I just don't like it as much as I like other names. I really like
Christopher as a middle name or boys, and I might use that even though I'm not
Christian.