The only thing I noticed about Pat Sajak was his obvious dislike for the Megaword category. He would feign enthusiasm as he introduced it, and he especially threw away the $500 bonus because the producers accepted pretty much ANY sentence.
I think Allen Ludden should get a free pass due to increasing illness. I saw an episode from his final week (his ACTUAL last show, not the one that was THOUGHT to be the last) and he seemed a bit more lost.
Drew Carey, unfortunately, gets my vote, due to a LOT of inconsistencies. Some shows he's good, some not so good, and sometimes his hosting fluctuates depending on the games played and the number of wins or losses. He STILL fumbles over rule explanations and there's NO excuse for that.
Bill Cullen wasn't TERRIBLE on TJW but if you compare TJW to his past shows, he's slower, and not as quick witted as he was in the past.
Gene Rayburn was subpar on BTB, but we all know he was woefully miscast and that he was led to believe that he would be allowed to do spontaneous, goofy things as he did on MG.
Agreed on Richard Karn... I think he pretty much just "ran on automatic" and did each show EXACTLY the same way. He missed a LOT of opportunities for snappy comments to bad answers. I think Karn got the nod because he's a genuinely likeable guy and completely different from Louie, but Feud needs great ad-libbers like John O'Hurley and Steve Harvey, both very competent Feud hosts in the recent years.
I think Jack Barry became worse too on TJW. It was pretty obvious the last couple seasons that he was getting bored, and he had "senior moments" in the bonus game, forgetting about natural triples. One of the late '84 episodes, he had time to fill after the audience game and had a lot of difficulty thinking of things to say... he was just rambling on.