Elmo pretty much took over in the early-mid 90's for some reason, which I never quite understood as I remember Elmo being on the show as far back as when I was a baby, which would be 1985-ish. He did little short cute sketches back then if I recall. Too much of him can get rather annoying.
The 80's had their elmo though, I remember Big Bird was the huge one in the entire show, either him or Oscar, with Kermit in Second. But even then Big Bird did not overshadow the other characters, he was just the most popular. Now you hardly see either of those two mentioned anymore, I don't even think snuffleuppagus is on there either.
I miss those good ole' days of Scanimate, Teeny Little Super Guy, and oranges singing Carmen songs.