Sounds like the twit-brained-verse is humming over possible choices for the new host. We've watched all of the "guest hosts" and observed the following:
The Best:
Ken Jennings - very professional as expected, somewhat like Alex style-wise. Interacted with the contestants well, too.
Mike Richards - did two weeks by necessity, filling in during the slot when no guest hosts were available. Did an amazing job. Knows the show better than anyone else alive and it showed. Also hosted in such a way that his role as host was almost invisible; you remembered the what the contestants did and don't remember him. He never upstaged them. Might get the job NOT because he tried to get it but because HIS bosses at Sony saw he was so good at it.
Buzzy Cohen - fun! He knows the "feel" of the show almost as well as Ken, but clearly took more joy in his host role. Of all the hosts, he was most entertaining and had the most fun interacting with the contestants. If I ever went on the show, he's the one I'd want at the podium.
Mayim Bialik - also clearly enjoyed the role, did a good job but not as enjoyable to watch as Buzzy.
Of these four, I'd choose Buzzy first, then Mike, then Mayim, then Ken. If you want to add "diversity points", then switch Mayim and Mike in the #2 and #3 slots but leave Buzzy and Ken 1st and 4th. I wouldn't bother with anyone else I've seen so far regardless of what I think of them in their normal roles; they're good at what they do, but not good enough at this to get the job.
The Good:
Aaron Rogers - who knew? Better than expected, wouldn't mind seeing him host again occasionally. Maybe he should be guest host for future Celebrity Jeopardy events.
David Faber - who knew 2? And the only one who bothered to mention when someone had a "runaway" win going into Final Jeopardy. I guess the other (non-financial-type) hosts are afraid of math.
The "Okay but this job is not you" - we appreciate their filling in and trying out, but they're not right for the permanent host job:
Anderson Cooper
Dr. Oz
Bill Whitaker
Savannah Guthrie
Dr. Gupta
Robin Roberts
George Stephanopoulus
Katie Couric
Levar Burton - special note here. Levar was a disappointment. While I'm a fan of his, he flubbed some responses, paused too long trying to figure out what to say on many others, yelled "Yes" too much and generally seemed to be trying too hard. I like Levar, but based on what I saw, I don't want him hosting. He's better suited for other things. I'm fully opposed to the psycho-fans who want him to host because they're groupies of his or want him for non-skill-based reasons. And if you specifically want a Star Trek actor, I'd bet Michael Dorn or Kate Mulgrew could do better than that, let them try out.
Pending: Joe Buck
Other : Would be curious to see how Neil DeGrasse Tyson would do.