David Faber would be my first choice
I'd never even heard of David before he did Jeopardy, but he was one of my favorite guest hosts. I'd definitely love to see him get another game show at some point.
As for Keke, I only vaguely knew of her work before she was announced as host, so I basically gave myself a crash course in her career. And man, she's done a LOT. Acting, singing, interviewing...she's got a very impressive resume so far, and I can absolutely see her doing a great job behind the Password desk. I second the rest of the board's thoughts in saying it's worth giving her a shot...every game show host has to have a first show, after all.