My suggestion was going to be The Duke.
With 3d printing being what it is we should be able to measure our hands and have a micro-factory just print a comfortable, ergonomic shell.
I do have an alternate suggestion - I got some very textured grip tape and applied it to every surface that I touch on my mouse and xbone controller. It gives me a lot more positive grip and control, I don't feel like I have to squeeze or anytthing to hold on to it, it's not slipping anywhere.