I should say that the old Grover makes the list. If you have watched Sesame Street in the past few years Grover shows up as a superhero, aka Grover 2.0, which is not so funny. Old Grover is cool though, especially this gag with the fat blue guy better known as Mr. Johnson.
4. The Count
I like math and so does this guy. I have always been a fan of his laugh.
3. Bert and Ernie
These guys are awesome.
1. Cookie Monster