Barker and Trebek on opposite ends, I think that's the easy part.
But it comes down to how we really want to divvy up the other two, so this is where I want to fork off based off what we're looking for.
If we want to have different decades represented, Barker and Trebek are the 70's and 80's, so you might go Monty Hall for the 60's and Regis Philbin for the 90's/00's.
If we go solely on notoriety as a game show host exclusively, I think Pat Sajak gets a spot solely due to Wheel's longevity, and maybe you get Peter Marshall for Hollywood Squares or Richard Dawson?
If we go off of Emmy nominations, it should be Sajak and Dick Clark. Although, if you want to extrapolate and put the 1st, 3rd, 16th, and 26th winners, like Mount Rushmore, it'd be Peter Marshall, Allen Ludden, Alex Trebek, and Ben Stein & Jimmy Kimmel sharing a spot