I voted for Riley, not because I like the name, but because its the only name on the list that has even a remote chance of being spelt correctly by other people. I've spent my whole life having people misspell my name, and I can tell you it isn't any fun. Genevieve is a lovely name, I don't understand why you want to mess with the spelling.
I like the name Genevieve but the spelling you've got is way too out there.
I also like Jacey (pronounced JAY-see, though, not jay-SEE), it's really pretty and simple.
Jennavieve - are you kidding.
if you like the name, fine, but spell it Genevieve
Jennavieve is really weird looking, like trying to make a trendy modern name into something it isn't
Jaycee - like the men's club the Jaycees. I've seen it spelled Jaci and could live with that, kinda cute actually
Riley Renee together, I don't like the double R. and I'm so tired of Riley - it's so equally boy/girl these days
my vote among all that would be just Jenna - or Janna as an alternative