I am completely with you on
Frederick.
Fred is so plain, and synaesthetically, it's such an ugly washed-out scarlet and tastes like bad tomatoes.
Friedrich is the same way - I love it but
Fritz is just kind of annoying. It's also the name of the dog next door. He's a nice dog, but still. He was the first
Fritz I had ever heard of. I don't hate it as much as I used to because of
Fritz Kreisler, but it will always sound like an old grey miniature schnauzer to me.