Seems like I can only add four at a time
Of course you recognise Mr. Hillenberg; I think Jeanie B and Ruth Ann are near the window and it looks like the Three Amigos - Ronnie G, Terry D and Gale R are back by the wall.
The second photo on top has many infamous characters including the Rocky the Magnificent, Two Dogs and Jeanie B.
Each 6th grade class had their own cheerleaders but I can't get the pictures bigger without mega distortion.