On a scale of zero (would fare very poorly) to ten (would fare excellent):
Gene Rayburn - TPIR
Cullen version: 3. Barker version: 8.
The looser structure of the CBS remake would have worked to Gene's advantage. Unlike earlier respondents, I believe Gene was able to exert as much control as necessary, and that he was careful not to control a situation too much.
Allen Ludden - Jeopardy!: 10.
Especially in the way I believe he would have challenged the home audience with FJ!, as trainman pointed out; yes, Alex does it to some extent (and so did Art Fleming,) but Allen might have done it better. Allen never forgot that, while the outcome of the game is important to the contestants, the chief reason for any game show's existence is to entertain the viewers.
Bill Cullen - Match Game
NBC version: 9. CBS version: 5.
EoTVG$2 doesn't list any sub hosts for MG '62 - '69, but I'd probably pass a polygraph test swearing that Bill filled in for him at least once. (Proof? -shrug- Ain't got any.) Of course, Bill's physical limitation would have altered MG '73 - '82's set, and perhaps the interaction with the celebs.
Bob Barker - Beat the Clock
Before he stopped dyeing his hair: 8. Silver Fox Bob: 4.
Keep in mind that Bob would have to explain DIFFERENT stunts every day, with hardly any repetition at all. One of the chief reasons he's still going strong at 80 is that he could do most of TPIR in his sleep.
Peter Marshall - Password: 8.
Pat Sajak - Concentration: 9.
I agree with Adam Nedeff that \"virtually anybody would work\" as hosts for these shows. Sajak's experience with emceeing a puzzle-solving show wouldn't hurt.
Alex Trebek - College Bowl: 10.
After 19 years of J!, plus the Geography Bee, etc., College Bowl would be a piece of cake.
Bob Eubanks - Hollywood Squares: 6
My concern re: Bob's hosting style would be that he'd get started on a four-minute interview riff with Charo based on the opening phrase of the question. (BE (agog): \"Really?!? THEN what happened?\") I've seen him do this on every show he's done, including CS '86.
Chuck Woolery - Blockbusters: 4 (7 if new, untimed bonus round)
The main game's questions are somewhat remeniscent of Greed's Terminators, but the show would need a different bonus round. (Heck, the Gold Run / Rush was too easy, anyway.)
Esoteric Eric, throwing his hat (a baseball cap from the replica of Stonehenge in Maryhill, WA) into the ring as the next host of Concentration