I've always named my cats what I thought was fitting for each cat, but I always add "y" or "ie" at the end of their names when I call for them. Right now my oldest is called Jazz, but when I'm calling him, I yell Jazzie. I also have a girl who I named Bille (Jean) and it's easy when I call for her.
So when I got a new kitten, I thought I might as well give her a name too with "ie" at the end. And I love True Blood, so Sookie was a fun and cute name.