Catherine. I wouldn't say I hate the nicknames, but I don't like any of them.
Cate would be my favorite, but it just doesn't excite me that much.
Theodore and
Edward are others. I'm really not fond of
Ed,
Ned,
Ted,
Teddy,
Eddie, etc.
I have the opposite problem with
Effie. I love it, but it needs a full name. I don't hate full names that it could be a nn for, but I don't love
Euphemia or
Josephine (and those are the only two I can think of that it could be short for).