Jessica is out for me because I know seven or eight in the same age brackets, three of them are in my grade at school and have to go by
Jess,
Jessi and
Jessika. (It is spelled with a 'c' legally, but this might be part of where names like Krystyannalynn come from... parents who grew up with a common name want to be unique, but don't really know how, except elaborating on names they already know.)
Based purely on sound,
Jessica is rather pretty and bright though. I like
Simon too.