Alex Trebek has passed (Update: new Jeopardy host stuff))

I still say the best choice is the one they didn't select. But if it had to be one of the two, I'd go with Mayim. Just more of a personality than Ken.
Ken just seems to have an air of superiority about him. I'd rather Mayim, as well, but I'm ok with the current formula. Both are miles ahead of Micheal Richards.